| SCS | Smart Control System | In English | → Electronics |
| SCSAP | SCS Adjust Panel | In English | → Vehicle engineering |
| SCSCP | SCS Control Panel | In English | → Vehicle engineering |
| SCSG | Single-Channel Signal Generator | In English | → Telecommunications |
| SCSS | Satellite Control Simulation System | In English | → Computer simulation → Spaceflight engineering, astronautics |
| SCSS | Sea-Cure Satellite System | In English | → Spaceflight engineering, astronautics |
| SCT | Signal Channel Transponder | In English | → Telecommunications |
| SCTE | S-Band Communication and Tracking Equipment | In English | → Telecommunications |
| SCTE | Spacecraft Central Timing Equipment | In English | → Spaceflight engineering, astronautics |
| SCTS | Secondary Clear To Send | In English | → Data → Telecommunications |
| SCU | Signal Conditioner Unit | In English | → Telecommunications |
| SCU | Shuttle Configuration Unit | In English | → Spaceflight engineering, astronautics |
| SCVE | Spacecraft Vicinity Equipment | In English | → Spaceflight engineering, astronautics |
| SD | Space Division | In English | → Spaceflight engineering, astronautics |
| SD | Signal Digitizer | In English | → Telecommunications |
| SD&EOSD | Strategic Defense and Electro-Optics Systems | In English | → Electrical engineering → Military engineering |
| SD&I | System Development and Integration | In English | → Engineering, technology |
| SD/AFSC | Space Division/Air Force Systems Command | In English | → 358 → Spaceflight engineering, astronautics |
| SD/IN | Space Division/Intelligence | In English | → Spaceflight engineering, astronautics |
| SD/SP | Space Division Directorate of Security | In English | → 355 → Spaceflight engineering, astronautics |
| SDAGE | Schéma Directeur d'Aménagement et de Gestion des Eaux | In French | → Hydrology → Environmental technology, water supply, waste management |
| SDAP | Shuttle Descent Analysis Program | In English | → Spaceflight engineering, astronautics |
| SDAT | Spacecraft Data Analysis Team | In English | → Spaceflight engineering, astronautics |
| SDC | Signal Data Converter | In English | → Telecommunications |
| SDC | Space Data Corporation | In English | → Spaceflight engineering, astronautics |
| SDCCC | Space Defense Command Communication Center | In English | → 355 → Telecommunications → Spaceflight engineering, astronautics |
| SDCD | Secondary Carrier Detect | In English | → Data → Telecommunications |
| SDCOC | Space Defense Command Operations Center | In English | → 355 → Telecommunications → Spaceflight engineering, astronautics |
| SDCS | SAIL Data Communications System | In English | → Telecommunications |
| SDD | Shuttle Design Directive | In English | → Spaceflight engineering, astronautics |
| SDE | Space Division Evaluator | In English | → Spaceflight engineering, astronautics |
| SDER | Schéma Directeur de l'Exploitation Routière | In French | → Transport and postal services |
| SDF | Shuttle Development Facility | In English | → Spaceflight engineering, astronautics |
| SDF | Single Degree of Freedom | In English | → Mechanical engineering |
| SDH | Synchronous Digital Hierarchy | In English | → Telecommunications |
| SDHS | Satellite Data Handling System | In English | → Data → Spaceflight engineering, astronautics |
| SDia | Seminars in Dialysis | In English | → Serial publications, periodicals → Pathology |
| SDIG | Société pour le Développement de l’Industrie du Gaz | In French | → Energy economics |
| SDIL | Spacecraft DCD Interface Logic | In English | → Human-computer interaction → Spaceflight engineering, astronautics |
| SDIO | Strategic Defense Initiative Organization | In English | → Organizations and associations → 355 → Military engineering |
| SDLV | Shuttle-Derived Launch Vehicle | In English | → Spaceflight engineering, astronautics |
| SDM | Shuttle Definition Manual | In English | → Spaceflight engineering, astronautics |
| SDM | Shuttle Data Management | In English | → Data → Spaceflight engineering, astronautics |
| SDMB | Shuttle Discrepancy Management Board | In English | → Spaceflight engineering, astronautics |
| SDMS | Shuttle Data Management System | In English | → Spaceflight engineering, astronautics |
| SDOF | Single Degree of Freedom | In English | → Mechanical engineering |
| SDP | Strategic Defense Program | In English | → 355 → Military engineering |
| SDP | Shuttle Data Processor | In English | → Data → Spaceflight engineering, astronautics |
| SDPC | Shuttle Data Processing Complex | In English | → Data → Spaceflight engineering, astronautics |
| SDPLV | Shuttle-Derived-Propellant Launch Vehicle | In English | → Spaceflight engineering, astronautics |
| SDQA | Space Division Quality Assurance | In English | → Quality management → Spaceflight engineering, astronautics |
| SDR | Spacelab Disposition Record | In English | → Spaceflight engineering, astronautics |
| SDRS | Shuttle Display Reconfiguration System | In English | → Human-computer interaction → Spaceflight engineering, astronautics |
| SDS | Satellite Data System | In English | → Data → Spaceflight engineering, astronautics |
| SDS | Strategic Defense System | In English | → Military engineering |
| SDS | Shuttle Dynamic Simulation | In English | → Spaceflight engineering, astronautics |
| SDS | Space Defense System | In English | → Military engineering → Spaceflight engineering, astronautics |
| SDS | Shuttle Dynamic Simulator | In English | → Spaceflight engineering, astronautics |
| SDSS | Space Division Shuttle Simulator | In English | → Spaceflight engineering, astronautics |
| SDT | Shuttle Data Tape | In English | → Data → Spaceflight engineering, astronautics |
| SDT | Structural Dynamic Test | In English | → Mechanical engineering |
| SDTA | Structural Dynamic Test Article | In English | → Mechanical engineering |
| SDTS | Satellite Data Transmission System | In English | → Spaceflight engineering, astronautics → Telecommunications |
| SDV | Shuttle-Derived Vehicle | In English | → Spaceflight engineering, astronautics |
| SDVP | Schéma Départemental à Vocation Piscicole | In French | → Fishing, hunting |
| SE | Systems Engineering | In English | → Engineering, technology |
| SE&A | System Engineering and Analysis | In English | → Engineering, technology |
| SE&I | Systems Engineering and Integration | In English | → Engineering, technology |
| SE&TD | System Engineering and Technical Direction | In English | → Engineering, technology |
| SEA | Samsø Energy Agency | In English | → Energy economics |
| SEA | Slovak Energy Agency | In English | → Energy economics |
| SeAc | Sensors and Actuators | In English | → Serial publications, periodicals → Electrical engineering → Electronics |
| SEACAM | Secretariat for Eastern African Coastal Area Management | In English | → International relations → Nature and society → Environmental technology, water supply, waste management |
| SEACE | Service Études et Appuis Contrôle Électrique | In French | → Electrical engineering |
| SEACF | Support Equipment Assembly and Checkout Facility | In English | → Mechanical engineering |
| SEADS | Shuttle Entry Air Data Sensor | In English | → Spaceflight engineering, astronautics |
| SEAM | System Engineering and Analysis Management | In English | → Management → Engineering, technology |
| SEB | Systems Engineering Branch | In English | → Engineering, technology |
| SEB | Société d'Embouteillage de Bourgogne | In French | → Beverage industry |
| SEC | Securities and Exchange Commission | In English | → Telecommunications |
| SEC | Sigma Energy Consulting | In English | → Energy economics |
| SÉCAM | Séquentiel Couleur à Mémoire | In French | → Telecommunications |
| SECM | Science and Engineering of Composite Materials | In English | → Serial publications, periodicals → 620 |
| SECO | Sustainer Engine Cutoff | In English | → Vehicle engineering |
| SECS | Shuttle Events Control Subsystem | In English | → Spaceflight engineering, astronautics |
| SECTM | Société d’Électricité et de Thermique du Centre et du Midi | In French | → Energy economics → Electrical engineering |
| SED | Space Engineering Document | In English | → Spaceflight engineering, astronautics |
| SEDPA | Syndicat des Entreprises de Distribution de Programmes Audiovisuels | In French | → Organizations and associations → Cinema, movies → Telecommunications |
| SEDR | Systems Engineering Department Report | In English | → Engineering, technology |
| SEE | Service de l'Énergie de l'État | In French | → Central administration → Energy economics |
| SEE | Société des Électriciens et des Électroniciens (www.see.asso.fr) | In French | → Organizations and associations → Electrical engineering → Electronics |
| SEEA | Serbian Energy Efficiency Agency | In English | → Energy economics |
| SEEC | Scottish Energy and Environment Conference | In English | → Organizations and associations → Nature → Energy economics |
| SEF | Singapore Epilepsy Foundation (www.epilepsy.com.sg) | In English | → Foundations → Neurology |
| SEF | Space Environmental Facility | In English | → Astronomy → Spaceflight engineering, astronautics |
| SEFA | Service d'Exploitation de la Formation Aéronautique | In French | → Specialized or (poly)technical colleges → Aeronautics, aircraft |
| SEG | Simulation Engineering Group | In English | → Computer simulation → Engineering, technology |
| SEG | Société Française de Gynécologie | In French | → Organizations and associations → Gynaecology |
| SEGUR | (Intégration de la) Sécurité routière dans la Gestion Urbaine | In French | → Transport and postal services → Regional planning |
| SEIF | Siondróm Easpa Imdhíonachta Faighte = AIDS | Acquired Immune Deficiency Syndrome | In English = SIDA | Syndrome d'Immuno-Déficience Acquise | In French = VIGS | Verworwe Immuniteitsgebreksindroom | In Afrikaans = SIDA | Síndrome de Inmuno-Deficiencia Adquirida | In Occitan = SIDA | Sindromo di Imuno-Defekteso Aquirita | In Ido = AIDS | Akirita Imuno-Deficita Simptomaro | In Esperanto = SIDA | Sindrome d'inmunodefizienzia aquirita | In Aragonese = СПИН | Синдром на придобитата имунна недостатъчност | In Bulgarian = QİÇS | Qazanılmış İmmun Çatışmazlığı Sindromu | In Azerbaijani = SIDA | Síndrome d'Immunodeficiència Adquirida | In Catalan = HIES | Hartutako Immuno Eskasiaren Sindromea | In Basque = SIDA | Síndrome de Inmunodeficiencia Adquirida | In Spanish = AIDS | Annlochd Inneamh Dìon-Slàinte | GD = ՁԻԱՀ | Ձեռքբերովի Իմունային Անբավարվածության Համախտանիշ | In Armenian = SCDI | Syndromis Comparatis Defectu Immunitatis | In Latin = 에이즈 | 후천성 면역 결핍 증후군 | In Korean = შიდსი | შეძენილი იმუნური დეფიციტის სინდრომი | In Georgian = СИДА | Синдромот на стекнат имунолошки дефицит | In Macedonian = СИДА | синдром стеченог имунолошког дефицита | In Serbian = AIDS | Akvirírani imúnski deficítni sindróm | In Slovenian = СПИД | Синдром приобретённого иммунного дефицита | In Russian = SIDA | Sindromul Imunodeficienţei Autodobândite | In Romanian = UHCW | Unquy hark'aypa chaskisqa waqlliynin | In Quechua = SIDA | Síndrome da imunodeficiência adquirida | In Portuguese = AIDS | Hội chứng Suy giảm Miễn dịch Mắc phải | In Vietnamese = СНІД | Cиндром набутого імунодефіциту | In Ukrainian = AIDS | Alınğan İmmun Defisit Síndromı | In Tatar = UKIMWI | Upungufu wa Kinga Mwilini | In Swahili |
In Irish | → Immunology and allergy → Infectious diseases |
| SEIMAT | Syndicat des Entreprises Internationnales de Matériels de Travaux Publics, Mines et Carrières, Bâtiment et Levage, Manutention (www.seimat.com) | In French | → Organizations and associations → Mining → Civil engineering → Building |
| SEIN | Stichting Epilepsie Instellingen Nederland (www.sein.nl) | In Dutch | → Foundations → Medicine |
| SEIS | Shuttle Experiments Integration Support | In English | → Spaceflight engineering, astronautics |
| SEIS | Spacelab Experiments Integration Support | In English | → Spaceflight engineering, astronautics |
| SEIST | System Engineering, Integration, and Support Team | In English | → Engineering, technology |
| SEIT | System Engineering, Integration, and Test | In English | → Engineering, technology |
| SEK | Svenska Elektriska Kommissionen | In Swedish | → Electrical engineering |
| SEL | Systems Electronics Laboratory | In English | → Research institutes → Electronics |
| SEL | Systems Engineering Laboratories | In English | → Research institutes → Engineering, technology |
| SEM | System Engineering Management | In English | → Engineering, technology |
| SEM | Space Environment Monitoring | In English | → Astronomy → Spaceflight engineering, astronautics |
| SEM | Shuttle Experiment Module | In English | → Spaceflight engineering, astronautics |
| SEM | Service d'Économie Maritime | In French | → Economics → Marine research, oceanography → Fishing, hunting |
| SEMA | Search Engine Marketing Association | In French | → Associations → Internet → 659 |
| SEMKO | Svenska Elektriska Materielkontrollanstalten | In Swedish | → Electrical engineering |
| SEMP | System Engineering Management Plan | In English | → Engineering, technology |
| SEMS | Space Environment Monitor System | In English | → Spaceflight engineering, astronautics |
| SEMWS | Survivable, Endurable Missile Warning System | In English | → 355 → Military engineering |
| SEN | Sistemul Electroenergetic Naţional | In Romanian | → Energy economics |
| SENACYT | Secretaría Nacional de Ciencia y Tecnología | In Spanish | → Public administration, government → Mathematics and natural sciences |
| SENAI | Serviço Nacional de Aprendizagem Industrial | In Portuguese | → Engineering, technology |
| SENE | Système Électrique Nord-Est | In French | → Electrical engineering |
| SENSE | Security-enhanced Near Field Communication Systems | In English | → Telecommunications |
| SEO | Search Engine Optimization | In English | → Internet → 659 |
| SEO | Special Engineering Order | In English | → Engineering, technology |
| SEOS | Synchronous Earth Observation Satellite | In English | → Astronomy → Spaceflight engineering, astronautics |
| SEP | Shuttle Electronics Package | In English | → Electronics → Spaceflight engineering, astronautics |
| SEP | Solar Electric Propulsion | In English | → Energy economics → Electrical engineering |
| SEP | Space Electronics Package | In English | → Electronics → Spaceflight engineering, astronautics |
| SEP | Standard Electronic Package | In English | → Electronics |
| SEP | Systems Engineering Plan | In English | → Engineering, technology |
| SEP | Société Européenne de Propulsion | In French | → Vehicle engineering |
| SEP | Sclérose en plaques | In French | → Pathology |
| SEPAP | Shuttle Electrical Power Analysis Program | In English | → Electrical engineering → Spaceflight engineering, astronautics |
| SEPAR | Shuttle Electrical Power Analysis Report | In English | → Electrical engineering → Spaceflight engineering, astronautics |
| SEPS | Solar Electric Propulsion System | In English | → Electrical engineering → Spaceflight engineering, astronautics |
| SEPTEN | Service Études et Projets Thermiques Et Nucléaires | In French | → Energy economics → Nuclear technology |
| SER | Sociedad Española de Radiodifusión | In Spanish | → Telecommunications |
| SER | Sources d'Énergie Renouvelable | In French | → Energy economics |
| SER | System Engineering Review | In English | → Engineering, technology |
| SERA | Société d'Étude et Réalisation Automobile | In French | → Automobile manufacturing |
| SERAA | Système Électrique Rhône-Alpes Auvergne | In French | → Electrical engineering |
| SERAM | Société d'Études et de Recherches de l'École Nationale Supérieure d'Arts et Métiers | In French | → Research policy → Specialized or (poly)technical colleges → Engineering, technology |
| SERB | Systems Engineering Review Board | In English | → Engineering, technology |
| SERB | Shuttle Engineering Review Board | In English | → Spaceflight engineering, astronautics |
| SERC | Solar Energy Research Center | In English | → Energy economics |
| SERCE | Syndicat des Entrepreneurs de Réseaux et de Constructions Électriques | In French | → Electrical engineering → Civil engineering |
| SERIESX | Satellite Emission Range Infrared Earth Sent | In English | → Spaceflight engineering, astronautics |
| SERNAM | SERvice NAtional de Messageries | In French | → Transport and postal services |
| SERS | Shuttle Enhanced Reconfiguration System | In English | → Spaceflight engineering, astronautics |
| SERS | Shuttle Equipment Record System | In English | → Spaceflight engineering, astronautics |
| SERT | Space Electrical Rocket Test | In English | → Electrical engineering → Spaceflight engineering, astronautics |
| SeRv | Sensor Review | In English | → Serial publications, periodicals |
| SES | Systems Engineering Simulator | In English | → Engineering, technology |
| SES | Satellite Earth Stations & Systems | In English | → Spaceflight engineering, astronautics |
| SES | Shuttle Engineering Simulator | In English | → Spaceflight engineering, astronautics |
| SES | Shuttle Engineering Simulation | In English | → Spaceflight engineering, astronautics |
| SESA | Special-Equipment Stowage Assembly | In English | → Mechanical engineering |
| SESAR | Single European Sky ATM Research | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| SESC | Shuttle Events Sequential Control | In English | → Spaceflight engineering, astronautics |
| SeScT | Semiconductor Science Technology | In English | → Serial publications, periodicals → Electronics |
| SESE | Système Électrique Sud-Est | In French | → Electrical engineering |
| SESKO | Sähkö- ja elektroniikka-alan standardisointijärjestö | In Finnish | → Standardization → Electronics |
| SESL | Space Environment(al) Simulation Laboratory | In English | → Research institutes → Spaceflight engineering, astronautics |
| SESMAT | Santé Et Satisfaction des Médecins Au Travail | In French | → Labour, labour economics → Medicine |
| SESP | Space Experiment to Support Program | In English | → Spaceflight engineering, astronautics |
| SeSTS | Semiconductor Science Technology Supplement | In English | → Serial publications, periodicals → Electronics |
| SET | Système Électrique Transport | In French | → Electrical engineering |
| SET | Solar Energy Thermionic | In English | → Energy economics |
| SET | Secure Electronic Transaction | In English | → Networks, communication → Telecommunications |
| SETA | System Engineering and Technical Assistance | In English | → Engineering, technology |
| SETAC | Systems Engineering Technical Advancement Center | In English | → Engineering, technology |
| SETAC | System Engineering and Technical Assistance Contractor | In English | → Engineering, technology |
| SETC | State Express Transport Corporation | In English | → Transport and postal services |
| SETC | Small Engine Technology Conference | In English | → Organizations and associations → Vehicle engineering |
| SETC | Société d'Électronique et de Télécommunication du Centre | In French | → Electronics → Telecommunications |
| SETC | Société d'Exploitation des Transports Chazot | In French | → Transport and postal services |
| SETELI | Suomen Erityisteknisten Liitto | In Finnish | → Organizations and associations → Engineering, technology |
| SETF | Small-Engine Test Facility | In English | → Vehicle engineering |
| SETHY | Société pour l’Environnement et les Travaux HYdrauliques | In French | → Civil engineering |
| SETP | System Engineering Test Phase | In English | → Engineering, technology |
| SETRA | Service d'Études Techniques des Routes et Autoroutes | In French | → Civil engineering → Transport and postal services |
| SETRAL | SErvice des TRAnsports Lourds | In French | → Transport and postal services |
| SEV | Schweizerische Eisenbahn- und Verkehrspersonal-Verband | In German | → Automobile manufacturing → Rail transport engineering |
| SEV | Slovenský elektrotechnický výbor | In Slovak | → Electrical engineering |
| SEVN | Syndicat de l’Édition Vidéo Numérique | In French | → Organizations and associations → Computer-based techniques → Telecommunications |
| SEWB | System Engineering Work Bench | In English | → Engineering, technology |
| SEWG | Sustaining Engineering Working Group | In English | → Engineering, technology |
| SEWS | Satellite Early Warning System | In English | → Spaceflight engineering, astronautics |
| SF | Signaling Frequency | In English | → Telecommunications |
| SFA | Sun-Finder Assembly | In English | → Spaceflight engineering, astronautics |
| SFA | Swedish Foundry Association | In English | → Associations → Metallurgy |
| SFACI | Software Flight Article Configuration Inspection | In English | → Software → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| SFAIC | Société Française d'Allergologie et d'Immunologie Clinique | In French | → Organizations and associations → Immunology and allergy |
| SFAR | Société Française d'Anesthésie et de Réanimation | In French | → Organizations and associations → Anesthesiology |
| SFBMN | Société Française de Biologie et Médecine Nucléaire | In French | → Organizations and associations → Biological sciences → Medicine |
| SFC | Société Française du Cancer | In French | → Organizations and associations → Oncology |
| SFC | Société Française de Céramique | In French | → Organizations and associations → 666 |
| SFC | Specific Fuel Consumption | In English | → Vehicle engineering |
| SFCI | Société Française de Construction Immobilière | In French | → Building |