| T | Tera - Tesla - Tritium | - | Astronomy |
| T/O | Theatre Of Operations | - | Astronomy |
| TA | Target Acquisition - Teaching Assistant -Tera-ampere -Territorial Army (UK) -Tristan Da Cunha (ISO 3166 Digram) | - | Astronomy |
| TA | Tamil Language (ISO 639-1 Code) | - | Astronomy |
| TA | Tantalum | - | Astronomy |
| TAA | Transparency Anti-Aliasing | - | Astronomy |
| TAACOM | U.S. Theater Army Area Command | - | Astronomy |
| TAADCOORD | Theatre Army Air Defence Co-ordinator | - | Astronomy |
| TAAR | Trace Amine-Associated Receptor | - | Astronomy |
| TAC | U.S. Tactical Air Command (1946-1992) | - | Astronomy |
| TACAMO | Take Charge And Move Out (U.S. Military) | - | Astronomy |
| TACAN | Tactical Air Navigation | - | Astronomy |
| TACC | Tactical Air Control Centre - (USAF) Tanker Airlift Control Center | - | Astronomy |
| TACCO | Tactical Coordinator | - | Astronomy |
| TACCSF | U.S. Theater Aerospace Command & Control Simulation Facility | - | Astronomy |
| TACDAR | Tactical Detection And Reporting | - | Astronomy |
| TACP | Tactical Air Control Party - Technology Applications Certification Program | - | Astronomy |
| TACSOP | Tactical SOP (Standing Operating Procedure) | - | Astronomy |
| TADIL | Tactical Digital Information Link | - | Astronomy |
| TADL | Tactical Air Data Link (taddle) | - | Astronomy |
| TADSS | Training Aids | - | Astronomy |
| TAH | Tahitian Language (ISO 639-2 Code) | - | Astronomy |
| TAI | Target[ed] Area Of Interest | - | Astronomy |
| TAJ | Tom And Jerry | - | Astronomy |
| TAJT | Tom And Jerry Tales | - | Astronomy |
| TALES | Technical Advice And Lexicon For Enabling Simulation | - | Astronomy |
| TAM | Tamil Language (ISO 639-2 Code) | - | Astronomy |
| TANJ | There Ain't No Justice (used As Expletive In The Ringworld Novels) | - | Astronomy |
| TANP | Terrain-Aware Network Planner | - | Astronomy |
| TANSTAAFL | There Ain't No Such Thing As A Free Lunch (coined By Author Robert A. Heinlein In His The Moon Is A Harsh Mistress) | - | Astronomy |
| TARDIS | Time And Relative Dimensions In Space (from Doctor Who) | - | Astronomy |
| TAROT | T?lescope ? Action Rapide Pour Les Objets Transitoires (French | - | Astronomy |
| TAS | Tasmania (postal Symbol) | - | Astronomy |
| TASER | Thomas A. Swift's Electric Rifle | - | Astronomy |
| TASM | Tactical Air-to-Surface Missile | - | Astronomy |
| TAT | Tourism Authority Of Thailand | - | Astronomy |
| TAT | Tatar Language (ISO 639-2 Code) | - | Astronomy |
| TATP | TriAcetone TriPeroxide | - | Astronomy |
| TATT | Tired All The Time (medical Diagnosis In-joke) | - | Astronomy |
| TB | Tuberculosis | - | Astronomy |
| TB | Terbium | - | Astronomy |
| TBA | To Be Announced | - | Astronomy |
| TBBPA | TetraBromoBisPhenol-A | - | Astronomy |
| TBC | To Be Confirmed | - | Astronomy |
| TBD | To Be Determined | - | Astronomy |
| TBGRI | Tropical Botanic Garden And Research Institute (India) | - | Astronomy |
| TBM | Tactical Ballistic Missile - Theatre Ballistic Missile | - | Astronomy |
| TBT | Tributyltin | - | Astronomy |
| TC | Technetium | - | Astronomy |
| TC | Teracoulomb - Turks And Caicos (ISO 3166 Digram) - United Arab Emirates (FIPS 10-4 Country Code; From Trucial Coast States) | - | Astronomy |
| TCA | Transformational Communications Architecture -Turks And Caicos (ISO 3166 Trigram) | - | Astronomy |
| TCAA | Top Counter-Assault Agents | - | Astronomy |
| TCAS | Traffic Collision Avoidance System | - | Astronomy |
| TCCCS | Tactical Command | - | Astronomy |
| TCD | Chad (ISO 3166 Trigram) | - | Astronomy |
| TCG | Trusted Computing Group - TÂrkiye Cumhuriyeti Gemisi | - | Astronomy |
| TCHD | Truck Cargo Heavy Duty | - | Astronomy |
| TCL | Tool Command Language | - | Astronomy |
| TCP | Traffic Control Point - Transmission Control Protocol - Trichlorophenol | - | Astronomy |
| TCU | Texas Christian University | - | Astronomy |
| TCWMS | Tele-Center Workforce Management System | - | Astronomy |
| TD | Toon Disney | - | Astronomy |
| TDA | The Disney Afternoon | - | Astronomy |
| TDL | Tactical Data Link | - | Astronomy |
| TDM | Time-Division Multiplexing | - | Astronomy |
| TDMA | Time Division Multiple Access | - | Astronomy |
| TDP | Technology Demonstration Programme | - | Astronomy |
| TDRS | Tracking Data And Relay Satellite | - | Astronomy |
| TE | Tactical Exploitation -Testosterone To Epitestosterone Ratio -Tight End (football) | - | Astronomy |
| TE | Tellurium | - | Astronomy |
| TE | Telugu Language (ISO 639-1 Code) | - | Astronomy |
| TEAL | Tasman Empire Airways Limited | - | Astronomy |
| TEAM | Together Everyone Achieves More | - | Astronomy |
| TED | Technology Entertainment Design Prize | - | Astronomy |
| TEETH | Tried Everything Else | - | Astronomy |
| TEL | Transporter | - | Astronomy |
| TEL | Telugu Language (ISO 639-2 Code) | - | Astronomy |
| TELAR | Transporter | - | Astronomy |
| TEMO | Training | - | Astronomy |
| TENCAP | Tactical Exploitation Of National Capabilities | - | Astronomy |
| TERS | Tactical Event Reporting System | - | Astronomy |
| TES | Tactical Event System | - | Astronomy |
| TEST | Thesaurus Of Engineering And Scientific Terms | - | Astronomy |
| TEVES | Tensor Vector Scalar Theory | - | Astronomy |
| TF | French Southern Territories (ISO 3166 Digram) -Task Force -Terafarad | - | Astronomy |
| TFMPP | Trifluorophenylmethylpiperazine | - | Astronomy |
| TFR | Total Fertility Rate | - | Astronomy |
| TFT | Thin-Film Transistor | - | Astronomy |
| TG | Tajik Language (ISO 639-1 Code) | - | Astronomy |
| TG | Teragram | - | Astronomy |
| TG | Togo (ISO 3166 Digram) | - | Astronomy |
| TGIF | Thank God It's Friday | - | Astronomy |
| TGK | Tajik Language (ISO 639-2 Code) | - | Astronomy |
| TGL | Tagalog Language (ISO 639-2 Code) | - | Astronomy |
| TGO | Togo (ISO 3166 Trigram) | - | Astronomy |
| TGT | Target | - | Astronomy |
| TGV | Tanjong Golden Village - Test Generation With Verification - Train ? Grande Vitesse (French For High-Speed Train) | - | Astronomy |
| TH | Terahenry - Thailand (ISO 3166 And FIPS 10-4 Country Code Digram) | - | Astronomy |
| TH | Thai Language (ISO 639-1 Code) | - | Astronomy |
| TH | Thorium | - | Astronomy |
