| SDD | Systems Development Device | In English | |
| SDDD | Software Detailed Design Document | In English | → Software |
| SDDL | Software Design and Document Language | In English | → Software |
| SDDS | Special Data Dissemination Standards | In English | → Standardization → Data |
| SDDS | Sony Dynamic Digital Sound | In English | → Cinema, movies |
| SDE | Software Development Environment | In English | → Software |
| SDE | Space Division Evaluator | In English | → Spaceflight engineering, astronautics |
| SDEF | Service Development Evaluation Facility | In English | |
| SDF | Safing and Deservicing Facility | In English | |
| SDF | Shuttle Development Facility | In English | → Spaceflight engineering, astronautics |
| SDF | Simulation Data File | In English | → Computer simulation |
| SDF | System Development Facility | In English | |
| SDF | Single Degree of Freedom | In English | → Mechanical engineering |
| SDF | Software Development Facility | In English | → Software |
| SDF | Software Development File | In English | → Software |
| SDG | Strap-Down Gyro | In English | |
| SDH | System Definition Handbook | In English | |
| SDH | Software Development Handbook | In English | → Software |
| SDH | Synchronous Digital Hierarchy | In English | → Telecommunications |
| SdHO | Shubnikov-de Haas Oscillation | In English | → Electricity, magnetism, electromagnetism |
| SDHS | Satellite Data Handling System | In English | → Data → Spaceflight engineering, astronautics |
| SDI | Strategic Defense Initiative | In English | → 355 |
| SDI | Selective Dissemination of Information | In English | → Libraries |
| SDia | Seminars in Dialysis | In English | → Serial publications, periodicals → Pathology |
| SDIF | Software Development and Integration Facility | In English | → Software |
| SDIL | Spacecraft DCD Interface Logic | In English | → Human-computer interaction → Spaceflight engineering, astronautics |
| SDIO | Strategic Defense Initiative Office | In English | → 355 |
| SDIO | Strategic Defense Initiative Organization | In English | → Organizations and associations → 355 → Military engineering |
| SDIP | Strategic Defense Initiative Program | In English | → 355 |
| SDK | Software Development Kit | In English | → Software |
| SDL | Simple Directmedia Layer | In English | → Software |
| SDL | System Description Language | In English | |
| SDL | Software Development Laboratory | In English | → Research institutes → Software |
| SDL | Software Development Library | In English | → Software |
| SDL | Standard Distribution List | In English | |
| SDL | System Design Language | In English | |
| SDL | Scenario Description Language | In English | |
| SDL | SAIL Difference List | In English | |
| SDLP | Social Democratic and Labour Party = PSDLO | Páirtí Sóisialta Daonlathach an Lucht Oibre | In Irish |
In English | → Political parties and movements |
| SDLV | Shuttle-Derived Launch Vehicle | In English | → Spaceflight engineering, astronautics |
| SDM | Shuttle Data Management | In English | → Data → Spaceflight engineering, astronautics |
| SDM | Subsystem Design Manual | In English | |
| SDM | Shuttle Definition Manual | In English | → Spaceflight engineering, astronautics |
| SDM | System Definition Manual | In English | |
| SDM | Security Document Management | In English | → Knowledge management |
| SDMB | Shuttle Discrepancy Management Board | In English | → Spaceflight engineering, astronautics |
| SDMS | Shuttle Data Management System | In English | → Spaceflight engineering, astronautics |
| SDN | Safety Discrepancy Notice | In English | |
| SDN | Software Development Note | In English | → Software |
| SDNS | Secure Data Network System | In English | → Data → Networks, communication |
| SDOF | Single Degree of Freedom | In English | → Mechanical engineering |
| SDOPS | Strategic Defense Operational Planning Support | In English | → 355 |
| SDP | Site Data Processor | In English | → Data |
| SDP | Subsystem Development Plan | In English | |
| SDP | Strategic Defense Program | In English | → 355 → Military engineering |
| SDP | Sensor Data Processing | In English | → Computer science |
| SDP | Standard Data Processor | In English | → Hardware |
| SDP | Shuttle Data Processor | In English | → Data → Spaceflight engineering, astronautics |
| SDP | Software Development Plan | In English | → Software |
| 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 | Software Design Review | In English | → Software |
| SDR | Systems Definitions Review | In English | |
| SDR | System Design Review | In English | |
| SDR | Storage Data Register | In English | → Data |
| SDR | Spacelab Disposition Record | In English | → Spaceflight engineering, astronautics |
| SDR | Software Design Requirement | In English | → Software |
| SDR | Series Dissipating Regulator | In English | |
| SDR | Serial Data Receiver | In English | → Data |
| SDR | Sensor Data Record | In English | → Data |
| SDR | Special Drawing Right | In English | → Finance |
| SDRAM | Synchronous Dynamic Random Access Memory | In English | → Memories |
| SDRB | Software Design Review Board | In English | → Software |
| SDRL | Subcontract(or) Data Requirements List | In English | → 3474 |
| SDRS | Shuttle Display Reconfiguration System | In English | → Human-computer interaction → Spaceflight engineering, astronautics |
| SDS | Simulation Data Subsystem | In English | → Computer simulation |
| SDS | Smoke Detector System | In English | |
| SDS | Software Design Specification | In English | → Software |
| SDS | Space Defense System | In English | → Military engineering → Spaceflight engineering, astronautics |
| SDS | Steering and Damping Subsystem | In English | |
| SDS | Shuttle Dynamic Simulator | In English | → Spaceflight engineering, astronautics |
| SDS | Shuttle Dynamic Simulation | In English | → Spaceflight engineering, astronautics |
| SDS | Strategic Defense System | In English | → Military engineering |
| SDS | Scientific Data System | In English | → Data |
| SDS | Satellite Data System | In English | → Data → Spaceflight engineering, astronautics |
| SDS | Sisters of the Divine Saviour | In English | → Roman catholic church |
| SDS-PAGE | Sodium Dodecylsulfate-Polyacrimide Gel Electrophoresis | In English | → Biological sciences |
| SDSA | Synthesis-Dependant Strand Annealing | In English | → Genetics |
| SDSC | San Diego Supercomputing Center | In English | → Computer science |
| SDSC | Strategic and Defence Studies Centre | In English | → 355 |
| SDSS | Space Division Shuttle Simulator | In English | → Spaceflight engineering, astronautics |
| SDSS | South Delta Secondary School | In English | → Education |
| SDSS | Sloan Digital Sky Survey | In English | → Astronomy |
| 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 |
| SDVF | Software Development and Verification Facility | In English | → Software |
| SE | System Evaluator | In English | |
| SE | Systems Engineering | In English | → Engineering, technology |
| SE | System Element | In English | |
| SE | System Effectiveness | In English | |
| SE | Support Equipment | In English | |
| SE | Survivability-Endurance | In English | |
| SE | Software Engineering | In English | → Software |
| Se | Selenium = Se | Sélénium | In French = Se | Selenium | In Afrikaans = Se | سيلينيوم | In Arabic = Se | Селен | In Belarusian = Se | Селен | In Bulgarian = Se | সেলেনিয়াম | In Bengali = Se | Selen | In Bosnian = Se | Seleni | In Catalan = Se | Seleniu | In Corsican = Se | Selen | In Czech = Se | Selen | In Danish = Se | Selen | In German = Se | Σελήνιο | In Greek = Se | Seleno | In Esperanto = Se | Selenio | In Spanish = Se | Seleen | In Estonian = Se | سلنیوم | In Persian = Se | Seleeni | In Finnish = Se | Seleni | In Friulian = Se | Selenio | In Galician = Se | סלניום | In Hebrew = Se | सेलेनियम | In Hindi = Se | Selenij | In Croatian = Se | Selenyòm | In Haitian Creole = Se | Szelén | In Hungarian = Se | Սելեն | In Armenian = Se | Selenium | In Indonesian = Se | Selenio | In Ido = Se | Selen | In Icelandic = Se | Selenio | In Italian = Se | セレン | In Japanese = Se | lurcmu | In Lojban = Se | 셀레늄 | In Korean = Se | Selenium | In Latin = Se | Selen | In Letzeburgesh = Se | Selenas | In Lithuanian = Se | Selēns | In Latvian = Se | Селен | In Macedonian = Se | सेलेनियम | In Marathi = Se | Selen | In Low German = Se | Seleen | In Dutch = Se | Selen | In Nynorsk = Se | Selen | In Norwegian = Se | Selèni | In Occitan = Se | Selen | In Polish = Se | Selênio | In Portuguese = Se | Silinyu | In Quechua = Se | Seleniu | In Romanian = Se | Селен | In Russian = Se | Sileniu | In Sicilian = Se | Selen | In Serbo-Croatian = Se | Selén | In Serbian = Se | Selen | In Slovenian = Se | Селен | In Serbian = Se | Selen | In Swedish = Se | Seleni | In Swahili = Se | செலீனியம் | In Tamil = Se | ซีลีเนียม | In Thai = Se | Selenyum | In Turkish = Se | Селен | In Ukrainian = Se | Selen | In Uzbek = Se | 硒 | In Chinese |
In English | → Chemistry |
| 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 |
| SE/FAC | Support Equipment Facility | In English | |
| SEA | Scanning Electrostatic Analysis | In English | |
| SEA | Silicon Elastometer Ablator | In English | |
| SEA | Statistical Energy Analysis | In English | → Physics |
| SEA | Slovak Energy Agency | In English | → Energy economics |
| SEA | Samsø Energy Agency | In English | → Energy economics |
| SEa | Sociology of Education Association | In English | → Associations → Sociology → Education |
| SEA-EAT | South-East Asia Earthquake and Tsunami Blog | In English | → Seismology, earthquakes |
| 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 |
| SEACF | Support Equipment Assembly and Checkout Facility | In English | → Mechanical engineering |
| SEACSN | Southeast Asian Conflict Studies Network | In English | → Organizations and associations → Polemology |
| SEADS | Shuttle Entry Air Data Sensor | In English | → Spaceflight engineering, astronautics |
| SEAGA | Selective Employment of Airborne and Ground Alert | In English | |
| SEAHTP | South East Asian Historical Texts Project | In English | → Libraries → Language, linguistics, literature → History |
| SEAID | Support Equipment Abbreviated Items Description | In English | |
| SEAiT | Southeast Asian Images and Text | In English | → Libraries → Area studies |
| SEAL | Safety Evidence Assurance Level | In English | |
| SEAL | Sea Scout Advanced Leadership | In English | → Organizations and associations |
| SEAL | Software Engineering and Ada Lab(oratory) | In English | → Research institutes → Software |
| SEAL | Semantics-directed Environment Adaptation Language | In English | → Programming languages |
| SEAL | Software-Optimized Encryption Algorithm | In English | → Software → Mathematics |
| SEAM | System Engineering and Analysis Management | In English | → Management → Engineering, technology |
| SEAM | Southeast Asia Microform Project | In English | → Libraries → Area studies |
| SEAMEO | Southeast Asian Ministers of Education Organization | In English | → International relations → Central administration → Education |
| SEAP | Southeast Asia Program | In English | → Higher education, universities → Language, linguistics, literature → Geography, biography, history |
| SEAP | Southeast Asia Publications | In English | → Serial publications, periodicals → Area studies |
| SEAPG | Support Equipment Acquisition Planning Group | In English | → Maintenance and logistics |
| SEAR | South East Asia Research | In English | → Serial publications, periodicals → Area studies |
| SEARC | Southeast Asia Research Centre City | In English | |
| SEARO | South-East Asia Regional Office | In English | |
| SEARP | South-East Asia Rainforest Research Programme | In English | → Ecology |
| SEAS | School of East Asian Studies | In English | → Higher education, universities → Area studies |
| SEASIM | System Element Attrition Simulation | In English | |
| SEASREP | Southeast Asian Studies Regional Exchange Programme | In English | → Education → Area studies |
| SEASSI | Southeast Asian Studies Summer Institute | In English | → Area studies |
| SEATO | Southeast Asia Treaty Organization | In English | → Organizations and associations → International relations |
| SEATO | South-East Asia Treaty Organization | In English | → Organizations and associations → International relations |
| SEB | Source Evaluation Board | In English | |
| SEB | Scientific Equipment Bay | In English | |
| SEB | Support Equipment Building | In English | |
| SEB | Systems Engineering Branch | In English | → Engineering, technology |
| SEBIS | Semantics in Business Information Systems | In English | → Knowledge management → Semiotics |
| SEC | Securities and Exchange Commission | In English | → Telecommunications |
| SEC | Sigma Energy Consulting | In English | → Energy economics → Consulting |
| SEC | Split Expander Cycle | In English | |
| SEC | Source Evaluation Committee | In English | |
| SEC | Sequential Events Controller | In English | |
| SECAAS | Southeast Conference of the Association for Asian Studies | In English | → Associations → Area studies |
| SECB | Scientific Engineering Centre Biomass | In English | |
| SECI | South East European Co-operative Initiative | In English | → International relations |
| SECM | Science and Engineering of Composite Materials | In English | → Serial publications, periodicals → 620 |
| SECO | Sustainer Engine Cutoff | In English | → Vehicle engineering |
| SECO | State Secretariat for Economic Affairs | In English | → Economics → Central administration → 33972 |
| SECOQC | Secure Communication based on Quantum Cryptography | In English | |
| SECOR | Sequential Collation Or Range | In English | |
| SECS | Shuttle Events Control Subsystem | In English | → Spaceflight engineering, astronautics |
| SECS | Sequential Events Control System | In English | |
| SECS | Simulation/Experiment Control System | In English | |
| SED | Space Engineering Document | In English | → Spaceflight engineering, astronautics |
| SedG | Sedimentary Geology (www.elsevier.com/locate/sedgeo) | In English | → Serial publications, periodicals → Earth sciences |
| Sedim | Sedimentology | In English | → Serial publications, periodicals → Earth sciences |
| SEDR | Systems Engineering Department Report | In English | → Engineering, technology |
| SEE | Software Engineering Exercise | In English | → Software |
| SEE | Software Equality Evaluation | In English | → Software |
| SEE | Secondary Electron Emission | In English | |
| SEE-ECN | South East Europe Education Cooperation Network | In English | |
| SEEA | Serbian Energy Efficiency Agency | In English | → Energy economics |
| SEEC | Scottish Energy and Environment Conference | In English | → Organizations and associations → Nature → Energy economics |
| SEECP | South East Europe Co-operation Process | In English | → International relations |
| SEECR | Southeastern Early China Roundtable | In English | → History |
| SEEJ | Society of Environmental Engineers Journal | In English | → Serial publications, periodicals → Environment, environmental sciences → Environmental technology, water supply, waste management |
| SEEMO | South East Europe Media Organisation | In English | → Newspapers, journalism |
| SEER | Scholars Engaged in Electronic Resources | In English | → Libraries |
| SEER | Sensor Experimental Evaluation and Review | In English | |
| SEERC | South East European Research Centre | In English | |
| SEF | Space Environmental Facility | In English | → Astronomy → Spaceflight engineering, astronautics |
| SEF | Singapore Epilepsy Foundation (www.epilepsy.com.sg) | In English | → Foundations → Neurology |
| SEG | Society of Economic Geologists | In English | → Organizations and associations → Economic geology |
| SEG | System Engineering Ground Rule | In English | |
| SEG | Simulation Engineering Group | In English | → Computer simulation → Engineering, technology |
| SEGeo | Seismology and Exploration Geophysics | In English | → Serial publications, periodicals → Geophysics → Seismology, earthquakes |
| SEHK | Stock Exchange Hong Kong | In English | → Financial markets |
| SEI | Space Exploration Initiative | In English | |
| SEI | Support Equipment Installation | In English | → Maintenance and logistics |
| SEI | Seller End Item | In English | |
| SEI | Software Engineering Institute | In English | → Software |
| SEICO | Support Equipment Installation and Checkout | In English | → Maintenance and logistics |
| SEINIT | Security Expert INITiative | In English |