| TM | Torque Motor | In English | → Vehicle engineering |
| TMA | Trans Mediterranean Airways | In English | → Aeronautics, aircraft → Transport and postal services |
| TME | Transfer Multisort Electronic | In English | → Electronics |
| TMECO | Time of Main Engine Cutoff | In English | → Spaceflight engineering, astronautics |
| TMG | Thermal Meteoroid Garment | In English | → Spaceflight engineering, astronautics |
| TMI | Transmars Injection | In English | → Spaceflight engineering, astronautics |
| TMP | Thermo-Mécanique et Plasticité | In French | → 620 → Mechanical engineering → Chemical technology |
| TMR | TOPEX Microwave Radiometer | In English | → Spaceflight engineering, astronautics |
| TMS | Thermal Management Solutions | In English | → Energy economics |
| TNP | Traité de Non Prolifération des armes nucléaires | In French | → International relations → Military engineering → Nuclear technology |
| TNS | Total Network Solutions (www.tns.co.uk) | In English | → Hardware → 6218 → Telecommunications |
| TNT | Trinitrotoluol = TNT | Trinitrotoluè | In Catalan = TNT | Trinitrotoluen | In Czech = TNT | Trinitrotoluene | In English = TNT | Trinitrotolueno | In Esperanto = TNT | Trinitrotolueno | In Spanish = TNT | Trinitrotoluenori | In Basque = TNT | ترینیتروتولوئن | In Persian = TNT | Trinitrotoluène | In French = TNT | Trinitrotoluene | In Italian = TNT | Trinitrotoluolas | In Lithuanian = TNT | Trinitrotolueen | In Dutch = TNT | Trinitrotoluen | In Nynorsk = TNT | Trinitrotoluen | In Norwegian = TNT | Trinitrotolueno | In Portuguese = TNT | Trinitrotoluen | In Romanian = TNT | Тринитротолуол | In Russian = TNT | Trinitrotoluen | In Slovenian = ТНТ | Тринитротоулен | In Serbian = TNT | ทีเอ็นที | In Thai = TNT | Trinitrotoluen | In Turkish = ТНТ | Тринітротолуол | In Ukrainian |
In German | → Chemicals → Military engineering |
| TNT | Trinitrotoluen = ТНТ (look above) |
In Norwegian | → Chemicals → Military engineering |
| TNT | Trinitrotoluen = ТНТ (look above) |
In Romanian | → Chemicals → Military engineering |
| TNT | Тринитротолуол = ТНТ (look above) |
In Russian | → Chemicals → Military engineering |
| TNT | Trinitrotoluen = ТНТ (look above) |
In Slovenian | → Chemicals → Military engineering |
| TNT | ทีเอ็นที = ТНТ (look above) |
In Thai | → Chemicals → Military engineering |
| TNT | Trinitrotoluen = ТНТ (look above) |
In Nynorsk | → Chemicals → Military engineering |
| TNT | Trinitrotolueen = ТНТ (look above) |
In Dutch | → Chemicals → Military engineering |
| TNT | Trinitrotoluè = ТНТ (look above) |
In Catalan | → Chemicals → Military engineering |
| TNT | Trinitrotoluene = ТНТ (look above) |
In English | → Chemicals → Military engineering |
| TNT | Trinitrotolueno = ТНТ (look above) |
In Esperanto | → Chemicals → Military engineering |
| TNT | Trinitrotolueno = ТНТ (look above) |
In Spanish | → Chemicals → Military engineering |
| TNT | Trinitrotoluenori = ТНТ (look above) |
In Basque | → Chemicals → Military engineering |
| TNT | ترینیتروتولوئن = ТНТ (look above) |
In Persian | → Chemicals → Military engineering |
| TNT | Trinitrotoluène = ТНТ (look above) |
In French | → Chemicals → Military engineering |
| TNT | Trinitrotoluene = ТНТ (look above) |
In Italian | → Chemicals → Military engineering |
| TNT | Trinitrotoluolas = ТНТ (look above) |
In Lithuanian | → Chemicals → Military engineering |
| TNT | Trinitrotoluen = ТНТ (look above) |
In Turkish | → Chemicals → Military engineering |
| TNT | Trinitrotolueno = ТНТ (look above) |
In Portuguese | → Chemicals → Military engineering |
| TNT | Trinitrotoluen = ТНТ (look above) |
In Czech | → Chemicals → Military engineering |
| TO | Takeoff | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| TOI | Transfer Orbit Insertion | In English | → Spaceflight engineering, astronautics |
| TOP | Technical Office Protocol | In English | |
| TOPS | Transfer Orbit Perigee Stage | In English | → Spaceflight engineering, astronautics |
| TOS | Transfer Orbit Stage | In English | → Spaceflight engineering, astronautics |
| TOW | Tank and Orbiter Weight | In English | → Spaceflight engineering, astronautics |
| TP | Turbopump | In English | → Mechanical engineering |
| TP | Time to Perigee | In English | → Spaceflight engineering, astronautics |
| TPA | Turbopump Assembly | In English | → Mechanical engineering |
| TPL | Transpacific Landing | In English | → Spaceflight engineering, astronautics |
| TPMS | Tire Pressure Monitoring System | In English | → Automobile manufacturing |
| TPN | Tarif de Première Nécessité | In French | → Prices → Electrical engineering |
| TPOCP | Turbopump Oxidizer Cavity Purge | In English | → Mechanical engineering |
| TPSGC | Travaux Publics et Services Gouvernementaux Canada | In French | → Public administration, government → Civil engineering |
| TPV | Technologiepark Villach | In German | |
| TQFP | Thin Quad Flat Pack | In English | → Electronics |
| TR | Time to Retrofire | In English | → Spaceflight engineering, astronautics |
| TR/SBS | TeleOperator Retrieval/Skylab Boost System | In English | → Spaceflight engineering, astronautics |
| TRDDS | Teal Ruby Data Documentation System | In English | → Spaceflight engineering, astronautics |
| TRDF | Teal Ruby Data Formatter | In English | → Spaceflight engineering, astronautics |
| TRE | Teal Ruby Experiment | In English | → Spaceflight engineering, astronautics |
| TRE/ITU | Teal Ruby Experiment/Infrared Telescope Unit | In English | → Astronomy → Spaceflight engineering, astronautics |
| TREN | TRansport et ÉNergie | In French | → Energy economics → Transport and postal services |
| TrGRC | Geothermal Resources Council Transactions | In English | → Serial publications, periodicals → Earth sciences → Energy economics |
| TRS | Teal Ruby Spacecraft | In English | → Spaceflight engineering, astronautics |
| TSE | Transportation Support Equipment | In English | → Vehicle engineering → Transport and postal services |
| TSP | Trajectory Synthesis Program | In English | → Software → Spaceflight engineering, astronautics |
| TSP | Trajectory Shaping Program | In English | → Software → Spaceflight engineering, astronautics |
| TsPK | Tsentr Podgotovka Kosmonavti | In Russian | → Spaceflight engineering, astronautics |
| TSS | Tethered Satellite System | In English | → Spaceflight engineering, astronautics |
| TT | Thrust Termination | In English | → Vehicle engineering |
| TT&C | Tracking, Telemetry, and Control | In English | → Spaceflight engineering, astronautics |
| TT&C | Telemetry, Tracking, and Communications | In English | → Spaceflight engineering, astronautics → Telecommunications |
| TT&C | Tracking, Telemetry, and Command | In English | → Spaceflight engineering, astronautics |
| TTA | Time To Apogee | In English | → Astronomy → Spaceflight engineering, astronautics |
| TTA | Thermomechanical Test Area | In English | → Mechanical engineering |
| TTBS | Thames Traditional Boat Society | In English | → Organizations and associations → 6295 |
| TTC | Telemetry, Telecommand and Control | In English | → Spaceflight engineering, astronautics |
| TTCA | Thrust Translation Controller Assembly | In English | → Vehicle engineering |
| TTCV | Tracking, Telemetry, Command, and Voice | In English | → Spaceflight engineering, astronautics → Telecommunications |
| TTENP | Transport Électricité Normandie Paris | In French | → Electrical engineering |
| TTL | Transistor-Transistor Logic | In English | → Electronics |
| TTO | Technology Transfer Office | In English | |
| TTP | Time To Perigee | In English | → Astronomy → Spaceflight engineering, astronautics |
| TTP | Time Triggered Protocol | In English | |
| TUASB | Tokyo University Institute of Space and Aeronautical Science Bulletin | In English | → Serial publications, periodicals → Astronomy → Aeronautics, aircraft → 6297 |
| TUASR | Tokyo University Institute of Space and Aeronautical Science Report | In English | → Serial publications, periodicals → Astronomy → Aeronautics, aircraft → 6297 |
| TÜBİTAK | Türkiye Bilimsel ve Teknolojik Araştırma Kurumu | In Turkish | |
| TUFEJ | Tokyo University Faculty of Engineering Journal Series | In English | → Serial publications, periodicals |
| TUFER | Tokyo Denki University Faculty of Engineering Research Reports | In English | → Serial publications, periodicals |
| TURP | Tarifs d'Utilisation des Réseaux Publics | In French | → Electrical engineering |
| TV | Target Vehicle | In English | → Vehicle engineering |
| TV | Thrust Vector | In English | → Vehicle engineering |
| TV | Transport(er) Vehicle | In English | → Vehicle engineering |
| TVC | Thrust Vector Control | In English | → Vehicle engineering |
| TVCD | Thrust Vector Control Driver | In English | → Vehicle engineering |
| TVCS | Thrust Vector Control System | In English | → Vehicle engineering |
| TVE | Technology Validation Experiment | In English | |
| TVSA | Thrust Vector Servoamplifier | In English | → Vehicle engineering |
| TW | Technische Wetenschappen | In Dutch | |
| TW/AA | Tactical Warning/Attack Assessment | In English | → 355 → Military engineering |
| TZW | Technologiezentrum Wasser (www.tzw.de) | In German | → Research institutes → Environmental technology, water supply, waste management |
| U3P | Union pour la Promotion de la Propulsion Photonique | In French | → Spaceflight engineering, astronautics |
| UAEA | Uluslararası Atom Enerji Ajansı (www.iaea.org) = IAAE | Internacia Agentejo pri Atom-Energio | In Esperanto = IAEA | International Atomic Energy Agency | In English = AIEA | Agence Internationale de l'Énergie Atomique | In French = AIEA | Agenţia Internaţională pentru Energie Atomică | In Romanian = МААЕ | Международна агенция за атомна енергия | In Bulgarian = AIEA | Agència Internacional de l'Energia Atòmica | In Catalan = MAAE | Mezinárodní agentura pro atomovou energii | In Czech = IAEA | Det Internationale Atomenergiagentur | In Danish = IAEO | Internationale Atomenergieorganisation | In German = OIEA | Organismo Internacional de Energía Atómica | In Spanish = סבא"א | הסוכנות הבינלאומית לאנרגיה אטומית | In Hebrew = IAEA | International Atomenergie Agence | In Letzeburgesh = AIEA | Agenzia Internazionale per l'Energia Atomica | In Italian = IAEA | अंतर्राष्ट्रीय परमाणु ऊर्जा अधिकरण | In Hindi = MAAE | Меѓународна агенција за атомска енергија | In Macedonian = МАГАТЭ | Международное агентство по атомной энергии | In Russian = AIEA | Agência Internacional de Energia Atómica | In Portuguese = MAEA | Międzynarodowa Agencja Energii Atomowej | In Polish = МАГАТЕ | Міжнародне агентство з атомної енергії | In Ukrainian = IAEA | สำนักงานพลังงานปรมาณูระหว่างประเทศ | In Thai = EANA | Energia Atomikoaren Nazioarteko Agentzia | In Basque |
In Turkish | → International relations → Energy economics → Nuclear technology |
| UAPET | Updates in Applied Physics and Electrical Technology | In English | → Serial publications, periodicals → Electrical engineering |
| UAR | Upper Austrian Research | In English | → Research policy |
| UARS | Upper Atmosphere Research Satellite | In English | → Meteorology, climatology → Spaceflight engineering, astronautics |
| UASER | Ultrasound Amplification by Stimulated Emission of Radiation | In English | → Acoustics |
| UAW | United Auto Workers | In English | → Organizations and associations → Labour, labour economics → Automobile manufacturing |
| UCD | Urine Collection Device | In English | → Environmental technology, water supply, waste management |
| UCPTE | Union pour la Coordination de la Production et du Transport d’Électricité | In French | → Organizations and associations → Electrical engineering |
| UCTA | Urine Collection Transfer Assembly | In English | → Environmental technology, water supply, waste management |
| UEA | United Energy Associates | In English | → Energy economics → Electrical engineering → Environmental technology, water supply, waste management |
| UEA | Urban Exploration Alberta | In English | → Civil engineering |
| UEPG | Union Européenne des Producteurs de Granulats (www.uepg.eu) | In French | → Organizations and associations → Civil engineering → Building |
| UES | Unified Energy System = ЕЭС | Единые Энергетические Системы | In Russian |
In English | → Energy economics → Electrical engineering |
| UFE | Union Française de l’Électricité | In French | → Organizations and associations → Electrical engineering |
| UFO | Unidentifiziertes Flugobjekt = OVNI | Objet Volant Non Identifié | In French = OVNI | Objecte Volador No Identificat | In Catalan = НЛО | Неидентифициран летящ обект | In Bulgarian = OVNI | Objeto Volador No Identificado | In Spanish = UFO | Unidentified Flying Object | In English = UFO | Unknown Flying Object | In English = UFO | Uidentificeret flyvende objekt | In Danish = NIFO | Neidentigita Fluganta Objekto | In Esperanto = UFO | Unbekend fleanend objekt | In Frisian = עב"מ | עצם בלתי מזוהה | In Hebrew = OVNI | Oggetto Volante Non Identificato | In Italian = NLO | Neidentificēts lidojošs objekts | In Latvian = UFO | Uidentifisert flygende objekt | In Norwegian = UFO | Uidentifisert flygande objekt | In Nynorsk = NOL | Niezidentyfikowany Obiekt Latający | In Polish = OVNI | Objeto Voador Não Identificado | In Portuguese = OZN | Obiect Zburător Neidentificat | In Romanian = НЛО | Неопознанный летающий объект | In Russian = NLO | Neidentifikovani leteći objekat | In Serbo-Croatian |
In German | → Spaceflight engineering, astronautics |
| UFO | Unbekend fleanend objekt = OVNI, НЛО, NIFO, עב"מ, NLO, NOL, OZN (look above) |
In Frisian | → Spaceflight engineering, astronautics |
| UFO | Uidentifisert flygende objekt = OVNI, НЛО, NIFO, עב"מ, NLO, NOL, OZN (look above) |
In Norwegian | → Spaceflight engineering, astronautics |
| UFO | Unidentified Flying Object = OVNI, НЛО, NIFO, עב"מ, NLO, NOL, OZN (look above) |
In English | → Spaceflight engineering, astronautics |
| UFO | Unknown Flying Object = OVNI, НЛО, NIFO, עב"מ, NLO, NOL, OZN (look above) |
In English | → Spaceflight engineering, astronautics |
| UFO | Uidentificeret flyvende objekt = OVNI, НЛО, NIFO, עב"מ, NLO, NOL, OZN (look above) |
In Danish | → Spaceflight engineering, astronautics |
| UFO | Uidentifisert flygande objekt = OVNI, НЛО, NIFO, עב"מ, NLO, NOL, OZN (look above) |
In Nynorsk | → Spaceflight engineering, astronautics |
| UIC | Universal Instruments Corporation | In English | |
| UICC | Universal Integrated Circuit Card | In English | → Electronics |
| UIOM | Usine d'Incinération des Ordures Ménagères | In French | → Environmental technology, water supply, waste management |
| UKAEA | United Kingdom Atomic Energy Agency | In English | → Public administration, government → Energy economics → Nuclear technology |
| ULO | Unmanned Launch Operations | In English | → Spaceflight engineering, astronautics |
| ULV | Unmanned Launch Vehicle | In English | → Spaceflight engineering, astronautics |
| UMIF | Upper Mechanical Integration Frame | In English | → Mechanical engineering |
| UMO | Unmanned Orbital | In English | → Spaceflight engineering, astronautics |
| UMVF | Unmanned Vertical Flight | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| UNGG | Uranium Naturel Graphite Gaz | In French | → Nuclear technology |
| UNICEM | Union Nationale des Industries de Carrières et Matériaux de Construction (www.unicem.fr) | In French | → Organizations and associations → Mining → Civil engineering → Building |
| UNIDIR | United Nations Institute for Disarmament Research (www.unidir.org) | In English | → United Nations → Military engineering → Polemology |
| UNIPE | Unité Nationale de l’Ingénierie du Parc en Exploitation | In French | → Electrical engineering |
| UNIPEDE | UNion Internationale des Producteurs Et Distributeurs d'Énergie Électrique | In French | → Organizations and associations → Electrical engineering |
| UNIT | Université Numérique Ingénierie et Technologie | In French | → Higher education, universities → Central administration |
| UNITEC | Universidad Tecnológica Centroamericana | In Spanish | → Higher education, universities |
| UNOOSA | United Nations Office for Outer Space Affairs | In English | → United Nations → Astronomy → Spaceflight engineering, astronautics |
| UNPG | Union Nationale de Producteurs de Granulats (www.unpg.fr) | In French | → Organizations and associations → 626 → Building |
| UNPG | Union Nationale des Producteurs de Granulats | In French | → Organizations and associations → Civil engineering → Building |
| UNPSA | United Nations Programme on Space Applications | In English | → Serial publications, periodicals → United Nations → Astronomy → Vehicle engineering |
| UoSAT | University of Surrey Satellite | In English | → Higher education, universities → Spaceflight engineering, astronautics |
| UPB | Université Polytechnique de Bucarest | In French | → Specialized or (poly)technical colleges |
| UPB | Universitatea Politehnica (din) Bucureşti | In Romanian | → Specialized or (poly)technical colleges |
| UPS | Upright Perigee Stage | In English | → Spaceflight engineering, astronautics |
| UPS | Uninterruptible Power System | In English | → Electrical engineering |
| URA | Urine Receptacle Assembly | In English | → Environmental technology, water supply, waste management |
| URGC | Unité de Recherche en Génie Civil | In French | → Civil engineering → Building |
| USA | United Space Alliance (www.unitedspacealliance.com) | In English | → Spaceflight engineering, astronautics |
| USA/RC | Universities Space Automation/Robotics Consortium | In English | → Electrical engineering |
| USAM | Ufficio Generale Spazio Aereo e Meteorologia | In Italian | → Meteorology, climatology → Aeronautics, aircraft |
| USASDG | United States Army Space Defense Group | In English | → 355 623n → Spaceflight engineering, astronautics |
| USBI | United Space Booster, Incorporated | In English | → Spaceflight engineering, astronautics |
| USIRF | Union des Syndicats de l'Industrie Routière Française (www.usirf.com) | In French | → Organizations and associations → Civil engineering |
| USNS | United States Navy Ship | In English | → 359 → 6295 |
| USS | Unmanned Space Satellite | In English | → Spaceflight engineering, astronautics |
| USS | United States Ship | In English | → 6295 |
| USTL | Université des Sciences et Technologies de Lille | In French | → Higher education, universities |
| USTO | Université des Sciences et de la Technologie d'Oran | In French | → Specialized or (poly)technical colleges |
| UTA | Universidad Técnica de Ambato | In Spanish | → Specialized or (poly)technical colleges → Higher education, universities |
| UTAC | Union Technique de l'Automobile et du Cycle | In French | → Organizations and associations → Automobile manufacturing |
| UTB | Université Technique de Budapest | In French | → Specialized or (poly)technical colleges |
| UTBM | Université technologique de Belfort-Montbéliard | In French | → Specialized or (poly)technical colleges → Higher education, universities |
| UTBM | Université de Technologie de Belfort-Montbéliard | In French | → Higher education, universities |
| UTC | Université de Technologie de Compiègne | In French | → Specialized or (poly)technical colleges → Higher education, universities |
| UTC | United Technology Center | In English | |
| UTC | United Technologies Corporation | In English | |
| UTCB | Universitatea Tehnică de Construcţii din Bucureşti | In Romanian | → Higher education, universities → Civil engineering → Building |
| UTE | Union Technique de l'Électricite | In French | → Organizations and associations → Electrical engineering |
| UTE | Usina Termelétrica Norte Fluminense (www.utenortefluminense.com.br) | In Portuguese | → Energy economics → Electrical engineering |
| UTE | Union Technique de l'Électricité et de la Communication | In French | → Organizations and associations → Electrical engineering → Telecommunications |
| UTE | Universidad Técnológica Equinoccial | In Spanish | → Higher education, universities |
| UTE | Universidad Técnica Equinoccial | In Spanish | → Specialized or (poly)technical colleges → Higher education, universities |
| UTN | Universidad Técnica del Norte | In Spanish | → Specialized or (poly)technical colleges → Higher education, universities |
| UTP | Unshielded Twisted Pair | In English | → Electrical engineering |
| UTPL | Universidad Técnica Particular de Loja | In Spanish | → Specialized or (poly)technical colleges → Higher education, universities |
| UTS | Université Technique de Sofia | In French | → Specialized or (poly)technical colleges |
| UTS | Unmanned Teleoperator Spacecraft | In English | → Spaceflight engineering, astronautics |
| UVD | Undervoltage Device | In English | → Electrical engineering |
| UVF | Unmanned Vertical Flight | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| UVPE | UV/Video Processing Electronics | In English | → Image processing → Electronics |
| V | Volt | In many languages | → Electricity, magnetism, electromagnetism → Electrical engineering |
| VAA | Vehicle Assembly Area | In English | → Vehicle engineering |
| VAB | Vertical Assembly Building | In English | → Mechanical engineering |
| VAB | Véhicule de l'Avant Blindé | In French | → Automobile manufacturing → Military engineering |
| VAB | Vehicle Assembly Building | In English | → Vehicle engineering |
| VAC | Vehicle Assembly and Checkout | In English | → Vehicle engineering |
| VACTL | Vertical Assembly Component Test Laboratory | In English | → Research institutes → Mechanical engineering |
| VAL | Véhicule Automatique Léger | In French | → Vehicle engineering → Transport and postal services |
| VAT | Vibroacoustic Test | In English | → Acoustics → Mechanical engineering |
| VATA | Vibroacoustic Test Article | In English | → Acoustics → Mechanical engineering |
| VATF | Vibration and Acoustic Test Facility | In English | → Acoustics → Mechanical engineering |
| VCC | Voltage Change Controller | In English | → Electrical engineering |
| VCC | Vehicle Command Count | In English | → Vehicle engineering |
| VCC | Vehicle Crew Chief | In English | → Vehicle engineering |
| VCL | Vehicle Centerline | In English | → Vehicle engineering |
| VCN | Vehicle Configuration Number | In English | → Vehicle engineering |
| VCO | Voltage-Controlled Oscillator | In English | → Electrical engineering |
| VCO | Voltage Control Oscillator | In English | → Electrical engineering |
| VCO | Voltage Control Operator | In English | → Electrical engineering |
| VCÖ | Verkehrsclub Österreich (www.vcoe.at) | In German | → Organizations and associations → Vehicle engineering → Transport and postal services |
| VCP | Vehicle Control Processor | In English | → Hardware → Vehicle engineering |
| VCS | Vehicle Cargo System | In English | → Vehicle engineering |
| VCT | Voltage Control Transfer | In English | → Electrical engineering |
| VDE | Verband der Elektrotechnik, Elektronik und Informationstechnik | In German | → Organizations and associations → Electrical engineering → Electronics → Telecommunications |
| VDI | Verein Deutscher Ingenieure (www.vdi.de) | In German | → Organizations and associations |