| Acronym | Sense | Language | Topics | 
|---|---|---|---|
| TTP | Trends in Theoretical Physics | In English | → Serial publications, periodicals → Physics  | 
| TTRA | Travel and Tourism Research Association (www.ttra.com) | In English | → Associations → Tourism  | 
| TTSP | Transport Theory and Statistical Physics | In English | → Serial publications, periodicals → Physics  | 
| TTU | Timing Terminal Unit | In English | |
| TTVC | Test Termination and Verification Contractor | In English | |
| TTX | TinyOS Technology Exchange | In English | → Congresses → Operating systems → Electronics  | 
| TTY | Teletype | In English | → Telecommunications | 
| TU | Technical Utilization | In English | → Engineering, technology | 
| TU | Technology Utilization | In English | → Engineering, technology | 
| TU | Transport Unit | In English | |
| TUAG | Telecommunication Users Advisory Group | In English | → Organizations and associations → Telecommunications  | 
| TUASB | Tokyo University Institute of Space and Aeronautical Science Bulletin | In English | → Serial publications, periodicals → Astronomy → Aeronautics, aircraft → Astronautics  | 
| TUASR | Tokyo University Institute of Space and Aeronautical Science Report | In English | → Serial publications, periodicals → Astronomy → Aeronautics, aircraft → Astronautics  | 
| TUC | Trades Union Congress | In English | → Organizations and associations → Labour, labour economics  | 
| TUCAA | The Ultimate Computer Acronyms Archive (www.acronyms.ch) | In English | → Encyclopaedias, reference works → Computer hardware  | 
| TUFEJ | Tokyo University Faculty of Engineering Journal Series | In English | → Serial publications, periodicals → Engineering, technology  | 
| TUFER | Tokyo Denki University Faculty of Engineering Research Reports | In English | → Serial publications, periodicals → Engineering, technology  | 
| TUFI | Toughened Unipiece Fibrous Insulation | In English | |
| TUISR | Tokyo University Institute Industrial Science Report | In English | → Serial publications, periodicals → Mathematics and natural sciences → Applied sciences, technology  | 
| TUNEL | Terminal deoxynucleotidyltransferase-mediated dUTP-biotin Nick End Labeling | In English | → Biochemistry, biophysics | 
| TUSTEP | Tübingen System of TExt processing Programs | In English | |
| TV | Target Vehicle | In English | → Vehicle engineering | 
| TV | Television | In English | → Telecommunications | 
| TV | Thermal Vacuum | In English | |
| TV | Thrust Vector | In English | → Vehicle engineering | 
| TV | Transport(er) Vehicle | In English | → Vehicle engineering | 
| TVA | Temporary Variance Authority | In English | |
| TVA | Thrust Vector Alignment | In English | → Astronautics | 
| TVAR | Test Variance | In English | → Quality management | 
| TVC | Thermal Vacuum Chamber | In English | |
| TVC | Thrust Vector Control | In English | → Vehicle engineering | 
| TVCD | Thrust Vector Control Driver | In English | → Vehicle engineering | 
| TVCN | Tech Coast Venture Network | In English | |
| TVCS | Thrust Vector Control System | In English | → Vehicle engineering | 
| TVD | Total Variation Diminishing | In English | |
| TVE | Technology Validation Experiment | In English | → Engineering, technology | 
| TVE | Test Evaluation Experiment | In English | → Quality management | 
| TVEXPIS | TV Experiment Interconnecting Station | In English | → Telecommunications | 
| TVMA | Texas Veterinary Medical Association (www.tvma.org) | In English | → Associations → Veterinary medicine → United States  | 
| TVN | Test Verification Network | In English | → Quality management | 
| TVP | Test Verification Program | In English | → Quality management | 
| TVS | Toxic Vapor Suit | In English | |
| TVS | Transient Voltage Suppressor | In English | → Electronics | 
| TVS | Transient Voltage Suppression | In English | → Electronics | 
| TVSA | Thrust Vector Servoamplifier | In English | → Vehicle engineering | 
| TVSSIS | TV Subsystem Interconnecting Station | In English | → Telecommunications | 
| TVT | Thermal Vacuum Test | In English | |
| TVTA | Thermal Vacuum Test Article | In English | |
| TW | Tactical Warning | In English | |
| TW | Tail Wind | In English | |
| TW | Threat Warning | In English | |
| TW | Thumb Wheel | In English | |
| TW | Traveling Wave | In English | |
| TW/AA | Tactical Warning/Attack Assessment | In English | → Military affairs → Military engineering  | 
| TWD | Tail Wags Dog | In English | |
| TWG | Transition Working Group | In English | |
| TWL | Threat Wavelength | In English | |
| TWMF | Tumbling Waters Museum of Flags | In English | → Museums → Flags, banners  | 
| TWT | Transonic Wind Tunnel | In English | → Aerodynamics | 
| TWT | Traveling-Wave Tube | In English | → Electromagnetism | 
| TWTA | Travelling Wave Tube Amplifier | In English | |
| TWTA | Traveling-Wave Tube Amplifier | In English | → Electromagnetism | 
| TWU | Transportation Workers Union of America (www.twu.com) | In English | → Organizations and associations → Labour, labour economics → Transport and postal services → United States  | 
| TWX | Teletype Wire Transmission | In English | → Telecommunications | 
| TX | Transmit Channel | In English | → Telecommunications | 
| TX-0 | Transistorized Experimental computer zero | In English | → Computer hardware | 
| TxDOT | Texas Department of Transportation | In English | → Regional administration → Transport and postal services → Vehicle engineering → United States  | 
| TYLCV | Tomato Yellow Leaf Curl Virus | In English | → Virology → Agricultural sciences  | 
| TZB | The Zandvoort Boys | In English | → Organizations and associations → Sport, physical exercises  | 
| U | Uridine | In English | → Genetics → Biochemistry, biophysics  | 
| U | Uranium = U | Uranio | In Esperanto = U | Uranium | In French = U | Uran | In Tosk = U | يورانيوم | In French = U | Uran | In Azerbaijani = U | Уран | In Belarusian = U | Уран | In Bulgarian = U | ইউরেনিয়াম | In Bengali = U | Uranijum | In Bosnian = U | Urani | In Catalan = U | Uraniu | In Corsican = U | Uran | In Czech = U | Uran | In Danish = U | Uran | In German = U | Ουράνιο | In Greek = U | Uranio | In Spanish = U | Uraan | In Estonian = U | Uranio | In Basque = U | اورانیوم | In Persian = U | Uraani | In Finnish = U | Urani | In Friulian = U | Uranio | In Galician = U | אורניום | In Hebrew = U | Uranij | In Croatian = U | Iranyòm | In Haitian Creole = U | Urán | In Hungarian = U | Ուրան (տարր) | In Armenian = U | Uranium | In Indonesian = U | Uranio | In Ido = U | Úran | In Icelandic = U | Uranio | In Italian = U | ウラン | In Japanese = U | jinmrvurani | In Lojban = U | ಯುರೇನಿಯಮ್ | In Kannada = U | 우라늄 | In Korean = U | Uranium | In Latin = U | Uran | In Letzeburgesh = U | Uranas | In Lithuanian = U | Urāns | In Latvian = U | യുറേനിയം | In Malayalam = U | Ilhuicateōtepoztli | En Nahuatl = U | Uran | In Low German = U | Uranium | In Dutch = U | Uran | In Nynorsk = U | Uran | In Norwegian = U | Uran | In Polish = U | Urânio | In Portuguese = U | Uranyu | In Quechua = U | Uraniu | In Romanian = U | Уран | In Russian = U | यूरानियम | In Sanskrit = U | Uraniu | In Sicilian = U | Uranijum | In Serbo-Croatian = U | Urán | In Slovak = U | Uran | In Slovenian = U | Urani | In Albanian = U | Уранијум | In Serbian = U | Uran | In Swedish = U | Urani | In Swahili = U | யுரேனியம் | In Tamil = U | ยูเรเนียม | In Thai = U | Uranyo | In Tagalog = U | Uranyum | In Turkish = U | Уран | In Ukrainian = U | Urani | In Vietnamese = U | 鈾 | In Chinese  | 
In English | → Chemistry | 
| U&E | Usability & Ergonomie | In English | → Human-computer interaction | 
| UA | Urban Anthropology | In English | → Serial publications, periodicals → Anthropology → Sociology  | 
| UA | Uniform Allowance | In English | → Military affairs | 
| UAD | User Accommodation Document | In English | |
| UAE | United Arab Emirates | In English | → Geography | 
| uAEM | Universities Allied for Essential Medicines | In English | → Higher education, universities → Medicine  | 
| UAL | United Airlines (https://www.united.com) | In English | → Transport by air → United States  | 
| UAM | User Authentification Module | In English | → Software | 
| UAM | University Art Museum | In English | → Museums → Higher education, universities → Arts  | 
| UAM | United Adult Ministries | In English | → Christianity | 
| UAMS | University of Antwerp Management School | In English | → Higher education, universities → Management → Belgium  | 
| UAOD | The United Ancient Order Of Druids | In English | → Organizations and associations → Modern spiritual movements  | 
| UAPET | Updates in Applied Physics and Electrical Technology | In English | → Serial publications, periodicals → Engineering, technology → Electrical engineering  | 
| UAR | Upper Austrian Research (https://www.uar.at/) | In English | → Research institutes → Research policy → Engineering, technology → Austria  | 
| UARS | Upper Atmosphere Research Satellite | In English | → Meteorology, climatology → Astronautics  | 
| UART | Universal Asynchronous Receiver Transmitter | In English | → Telecommunications | 
| UART | Universal Asynchronous Receiver-Transmitter | In English | → Data → Networks, communication  | 
| UAS | Urban Aboriginal Strategy | In English | → Regional planning | 
| UASER | Ultrasound Amplification by Stimulated Emission of Radiation | In English | → Engineering, technology → Acoustics  | 
| UAW | United Auto Workers | In English | → Organizations and associations → Labour, labour economics → Automobile manufacturing  | 
| UB | Utility Bridge | In English | → Civil engineering → Construction  | 
| UBAA | University at Buffalo Alumni Association (www.alumni.buffalo.edu) | In English | → Associations → Higher education, universities  | 
| UBE | University at Buffalo Experience | In English | → Higher education, universities | 
| UBER | Undetected Bit Error Rate | In English | → Computer science | 
| UBF | University of Buffalo Foundation (http://ubfoundation.buffalo.edu) | In English | → Foundations → Higher education, universities  | 
| UBF | Unique Brand Factory (www.ubf.com.tr) | In English | → Advertising | 
| UBMD | University at Buffalo Medical Doctor | In English | → Higher education, universities → Medicine  | 
| UBR | Unspecified Bit-Rate | In English | → Computer science | 
| UC | Unsatisfactory Condition | In English | → Quality management | 
| UC | Ulcerative Colitis | In English | → Pathology | 
| UCA | Uniform Chart of Accounts | In English | |
| UCAF | Universal Cardholder Authentication Field | In English | → Computer-based techniques → Electronics  | 
| UCAR | Unsatisfactory Condition Action Report | In English | → Quality management | 
| UCC | Uniform Code Council | In English | → Organizations and associations | 
| UCC | Universal Checkout Console | In English | → Computer hardware → Human-computer interaction  | 
| UCC | Uniform Commercial Code | In English | → Trade | 
| UCD | Urine Collection Device | In English | → Environmental technology, water supply, waste management | 
| UCE | Unsolicited Commercial Email | In English | → Networks, communication → Telecommunications  | 
| UCEC | Universal Content Extented Classification | In English | → Computer science | 
| UCH | Ubiquitin Carboxy-terminal Hydrolase | In English | → Enzymes | 
| UCI | University Community Initiative | In English | → Higher education, universities | 
| UCKG | Universal Church of the Kingdom of God = EURD | Église Universelle du Royaume de Dieu | In French = IURD | Iglesia Universal del Reino de Dios | In Spanish = IURD | Igreja Universal do Reino de Deus | In Portuguese  | 
In English | → Christianity → Modern spiritual movements  | 
| UCL | University College London (https://www.ucl.ac.uk) | In English | → Higher education, universities → United Kingdom  | 
| UCLA | University of California, Los Angeles (www.ucla.edu) | In English | → Higher education, universities → United States  | 
| UCLAP | University of California Los Angeles - Astronomical Papers | In English | → Serial publications, periodicals → Astronomy → United States  | 
| UCN | Uniform Control Number | In English | |
| UCODEP | Unity and Cooperation for Development of People | In English | → Organizations and associations → Development  | 
| UCR | Unsatisfactory Condition Report | In English | → Quality management | 
| UCS | Universal Character Set | In English | → Writing systems → Data  | 
| UCS | Universal Control System | In English | |
| UCS | Utilities Control System | In English | |
| UCSC | University of California at Santa Cruz (https://www.ucsc.edu/) | In English | → Higher education, universities → United States  | 
| UCTA | Urine Collection Transfer Assembly | In English | → Environmental technology, water supply, waste management | 
| UCW | Understanding Children's Work and its Impact | In English | → Organizations and associations → Labour, labour economics → Fundamental rights  | 
| UDA | User-Developed Application | In English | → Software | 
| UDB | Update Buffer | In English | |
| UDC | Universal Decimal Classification = UDK | Universala Dekuma Klasifiko | In Esperanto = CDU | Classification Décimale Universelle | In French = UDC | Universele Decimale Classificatie | In Dutch = CDU | Clasificación Decimal Universal | In Spanish = UDC | Universel Decimal Classifikation | In Danish  | 
In English | → Libraries | 
| UDC | Utility Distribution Center | In English | |
| UDDI | Universal Description Discovery and Integration | In English | → Networks, communication → Telecommunications  | 
| UDF | Unit Development Folder | In English | |
| UDHR | Universal Declaration of Human Rights = UDHR | Universala Deklaracio de Homaj Rajtoj | In Esperanto = DUDH | Déclaration Universelle des Droits de l'Homme | In French = DUDH | Declaración Universal de los Derechos Humanos | In Spanish = GEAU | Giza Eskubideen Aldarrikapen Unibertsala | In Basque = VDLP | Všeobecná deklarace lidských práv | In Czech = UVMR | Universele Verklaring van Menseregte | In Afrikaans = DUDH | Declaración Universal dos Dereitos Humanos | In Galician = MSÞ | Mannréttindayfirlýsing Sameinuðu þjóðanna | In Icelandic = DUDU | Dichiarazione Universale dei Diritti Umani | In Italian = PDPC | Powszechna Deklaracja Praw Człowieka | In Polish = DUDH | Declaração Universal dos Direitos Humanos | In Portuguese = DUDO | Declaraţia Universală a Drepturilor Omului | In Romanian = ВДПЧ | Всеобщая декларация прав человека | In Russian = İHEB | İnsan Hakları Evrensel Bildirisi | In Turkish  | 
In English | → Human rights | 
| UDMH | Unsymmetrical Dimethylhydrazine | In English | → Chemical technology | 
| UDMH/H | Unsymmetrical Dimethylhydrazine Hydrazine Blend | In English | → Chemical technology | 
| UDO | Ultra Density Optical | In English | |
| UDOP | Ultrahigh Doppler | In English | |
| UDP | User Datagram Protocol | In English | → Networks, communication | 
| UDP/IP | User datagram protocol/Internet Protocol | In English | → Internet | 
| UDS | Universal Documentation System | In English | → Documentation → Knowledge management  | 
| UDS | Utility Distribution System | In English | |
| UDS | Uniform Data Systems | In English | → Data | 
| UDSF | United Democratic Sudan Forum | In English | → Political parties and movements | 
| UDTA | Ugandan Development Theater Association | In English | → Associations → Theatre  | 
| UDWDM | Ultra Dense Wavelength Division Multiplexing | In English | → Networks, communication → Telecommunications  | 
| UE | User Equipment | In English | |
| UEA | University of East Anglia (www.uea.ac.uk) | In English | → Higher education, universities → United Kingdom  | 
| UEA | Utah Education Association | In English | → Associations → Education → United States  | 
| UEA | United Energy Associates (www.uea.com) | In English | → Energy economics → Electrical engineering → Environmental technology, water supply, waste management  | 
| UEA | Urban Exploration Alberta | In English | → Civil engineering → Canada  | 
| UECBu | University Electro-Communications Bulletin | In English | → Serial publications, periodicals → Telecommunications  | 
| UEF | Union of European Federalists = UEF | Unio de la Europaj Federistoj | In Esperanto  | 
In English | → Political parties and movements | 
| UEFA | Union of European Football Associations (www.uefa.com) = UEFA | Union Européenne de Football Association | In French  | 
In English | → Organizations and associations → Football and rugby  | 
| UEN | Union for Europe of the Nations (www.uengroup.org) = UEN | Union pour l'Europe des nations | In French = UEN | Union für ein Europa der Nationen | In German = UEN | Unio por Eŭropo de Nacioj | In Esperanto = UEN | Unión por la Europa de las Naciones | In Spanish = UEN | Unión pola Europa das Nacións | In Galician = UEN | Unione per l'Europa delle Nazioni | In Italian = UEN | Unie voor een Europa van Nationale Staten | In Dutch = UEN | Unia na rzecz Europy Narodów | In Polish = UEN | União para a Europa das Nações | In Portuguese = UNE | Unionen för nationernas Europa | In Swedish  | 
In English | → Political parties and movements → European Union  | 
| UEP | Undergraduate Exchange Program | In English | → Education | 
| UER | Unique-Equipment Register | In English | |
| UES | Unified Energy System = ЕЭС | Единые Энергетические Системы | In Russian  | 
In English | → Energy economics → Electrical engineering  | 
| UETP | University Enterprise Training Partnership | In English | → Higher education, universities → Labour, labour economics  | 
| UFAS | Uniform Federal Accessibility Standards | In English | → Standardization | 
| UFAW | Universities Federation for Animal Welfare (www.ufaw.org.uk) | In English | → Organizations and associations → Higher education, universities → Veterinary medicine → United Kingdom  | 
| UFD | User File Directory | In English | → Software → Files  | 
| UFE | Uterine Fibroid Embolisation | In English | → Medicine | 
| UFO | Unidentified Flying Object = 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 | Unidentifiziertes Flugobjekt | In German = 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 English | → Astronautics | 
| UFO | Unknown Flying Object = OVNI, НЛО, NIFO, עב"מ, NLO, NOL, OZN (look above)  | 
In English | → Astronautics | 
| UFP | United Federation of Planets | In English | → Organizations and associations → Politics → Literature  | 
| UGC | University Grants Committee | In English | → Higher education, universities | 
| UGC | User Generated Content | In English | → Networks, communication → Computer-based techniques  | 
| UGL | Undergraduate Library | In English | → Libraries → Education  | 
| UGSJR | US Geological Survey Journal Research | In English | → Serial publications, periodicals → Earth sciences → United States  | 
| UHA | Ukrainian Historical Association | In English | → Associations → History  | 
| UHA | Urban History Association | In English | → Associations → 93031  | 
| UHCCI | Union of Hellenic Chambers of Commerce and Industry | In English | → Organizations and associations → Trade → Industry, industrial policy → Greece  | 
| UHF | Ultrahigh Frequency | In English | |
| UHF | Ultra High Frequency = УКВ | Ультракороткие волны | In Russian = UKW | Ultrakurzwelle | In German  | 
In English | → Telecommunications | 
| UHF/VHF | Ultra High Frequency/Very High Frequency | In English | → Telecommunications | 
| UHT | Umbilical Handling Technician | In English | |
| UI | User Interface | In English | → Human-computer interaction | 
| UIA | Uganda Investment Authority | In English | → 33972 | 
| UIC | University of Illinois at Chicago (www.uic.edu) | In English | → Higher education, universities → United States  | 
| UIC | Universal Instruments Corporation | In English | → Engineering, technology | 
| UIC | Unit Identification Code | In English | |
| UICB | International Union of Building Centres (www.uicb.org) | In English | → Organizations and associations → Construction  | 
| UICC | Universal Integrated Circuit Card | In English | → Electronics | 
| UIIP | User Integration Implementation Plan | In English | |
| UIMA | Unstructured Information Management Architecture | In English | → Software | 
| UIML | User Interface Markup Language | In English | → Programming languages → Human-computer interaction  | 
| UIMS | User Interface Management System | In English | → Human-computer interaction | 
| UIR | Universal Infrared Receiver | In English | → Computer hardware → Peripheral devices  | 
| UIRF | University of Iowa Research Foundation (http://research.uiowa.edu/techtransfer/) | In English | → Foundations → Higher education, universities → United States  | 
| UIT | Ultraviolet Imaging Telescope | In English | → Astronomy | 
| UIUC | University of Illinois at Urbana-Champaign | In English | → Higher education, universities → United States  | 
| UIUC DLI | University of Illinois at Urbana-Champaign Digital Library Initiative | In English | → Libraries → Data → United States  | 
| UIWG | User Interface Working Group | In English | → Human-computer interaction | 
| UK | United Kingdom | In English | → Geography | 
| UKAEA | United Kingdom Atomic Energy Agency | In English | → Public administration, government → Energy economics → Nuclear technology  | 
| UKERF | University of Kentucky Equine Research Foundation | In English | → Foundations → Zoology  | 
| UKERNA | United Kingdom Education and Research Networking Association | In English | → Associations → Education → Research policy  | 
| UKIB | United Kingdom Independent Broadcasting | In English | → Telecommunications | 
| UKIERI | United Kingdom-India Education Research Initiative (www.ukieri.org) | In English | → Education | 
| UKIPG | United Kingdom Interprofessional Group | In English | → Organizations and associations → Labour, labour economics  | 
| UkMJ | Ukranian Mathematical Journal = UkMaZ | Ukrainskii Matematicheskii Zhurnal | In Russian  | 
In English | → Serial publications, periodicals → Mathematics  |