| G | CSF -Granulocyte Colony-Stimulating Factor | - | Astronomy |
| G | Gauss | - | Astronomy |
| G | Gram | - | Astronomy |
| G1 | Assistant Chief-of-Staff | - | Astronomy |
| G10 | Group Of 10 (G7 + Belgium | - | Astronomy |
| G15 | Group Of 15 (subset Of G77 | - | Astronomy |
| G2 | Assistant Chief-of-Staff | - | Astronomy |
| G20 | Group Of 20 (G8 + Argentina | - | Astronomy |
| G24 | Group Of 24 (subset Of G77 | - | Astronomy |
| G3 | Many | - | Astronomy |
| G4 | Generation Four PowerPC Microprocessor -Assistant Chief-of-Staff | - | Astronomy |
| G5 | Generation Five PowerPC Microprocessor -Assistant Chief-of-Staff | - | Astronomy |
| G6 | Assistant Chief-of-Staff | - | Astronomy |
| G7 | Assistant Chief-of-Staff | - | Astronomy |
| G77 | Group Of 77 (issued From The United Nations Conference On Commerce And Development | - | Astronomy |
| G8 | Assistant Chief-of-Staff | - | Astronomy |
| G9 | Assistant Chief-of-Staff | - | Astronomy |
| GA | Gabon (ISO 3166 Digram) - The Gambia (FIPS 10-4 Country Code) - Georgia (postal Symbol) - Gigaampere | - | Astronomy |
| GA | Gallium - Gigaannum | - | Astronomy |
| GA | Irish Language (ISO 639-1 Code) | - | Astronomy |
| GAAR | General Anti-Avoidance Rule (tax Evasion) | - | Astronomy |
| GAB | Gabon (ISO 3166 Trigram) | - | Astronomy |
| GABA | Gamma-AminoButyric Acid | - | Astronomy |
| GAD | Generalized Anxiety Disorder | - | Astronomy |
| GALCIT | Guggenheim Aeronautical Laboratory | - | Astronomy |
| GANGY | Green Anorak | - | Astronomy |
| GAO | U.S. Government Accountability Office | - | Astronomy |
| GAW | Global Atmospheric Watch | - | Astronomy |
| GB | Gabon (FIPS 10-4 Country Code) - United Kingdom Of Great Britain And Northern Ireland (ISO 3166 Digram) | - | Astronomy |
| GBBC | Great Backyard Bird Count | - | Astronomy |
| GBE | Knight/Dame Grand Cross Of The Order Of The British Empire | - | Astronomy |
| GBH | Grievous Bodily Harm | - | Astronomy |
| GBP | United Kingdom Pound Sterling (ISO 4217 Currency Code) | - | Astronomy |
| GBR | United Kingdom Of Great Britain And Northern Ireland (ISO 3166 Trigram) | - | Astronomy |
| GBU | Glide-Bomb Unit - Global Business Unit | - | Astronomy |
| GC | East Germany (NATO Country Code; Obsolete 1990) -General Counsel -Gigacoulomb | - | Astronomy |
| GCCS | Global Command And Control System (geeks) | - | Astronomy |
| GCD | See Entry | - | Astronomy |
| GCF | Greatest Common Factor | - | Astronomy |
| GCI | Ground-controlled Interception | - | Astronomy |
| GCN | Gamma-ray Burst Coordination Network | - | Astronomy |
| GCS | Global Coordinate System | - | Astronomy |
| GCSE | General Certificate Of Secondary Education (UK) | - | Astronomy |
| GD | Gadolinium | - | Astronomy |
| GD | Grenada (ISO 3166 Digram) | - | Astronomy |
| GD | Scottish Gaelic Language (ISO 639-1 Code) | - | Astronomy |
| GDC | Game Developers Conference | - | Astronomy |
| GDC | General Dental Council | - | Astronomy |
| GDL | Game Definition Language | - | Astronomy |
| GDP | General Dental Practitioner (UK) - Gross Domestic Product | - | Astronomy |
| GDR | General Distribution Release (Microsoft Term For A Software Service Release; Between Hotfix And Service Pack) | - | Astronomy |
| GDR | German Democratic Republic (cf. DDR) | - | Astronomy |
| GDW | Game Designers Workshop | - | Astronomy |
| GE | General Electric - Genetic Engineering (cf. GM) -Georgia (ISO 3166 Digram) | - | Astronomy |
| GE | Germanium | - | Astronomy |
| GEBCO | General Bathymetric Chart Of The Oceans | - | Astronomy |
| GEC | Great Engineering Challenge | - | Astronomy |
| GED | General Education Development | - | Astronomy |
| GEEP | Geophysical Equipment Exploration Platform | - | Astronomy |
| GEL | Georgian Lari (ISO 4217 Currency Code) - Gilbert And Ellice Islands (ISO 3166 Trigram; Obsolete 1977) | - | Astronomy |
| GEMA | Gas And Electricity Markets Authority - Georgia Emergency Management Agency -Gesellschaft FÂr Musikalische AuffÂhrungs- Und Mechanische Vervielf?ltigungsrechte (German Performance Rights Organisation) -Global Engine Manufacturing Alliance | - | Astronomy |
| GEN | Full General (four Stars) In The U.S. Army | - | Astronomy |
| GEO | Geostationary Earth Orbit -Georgia (ISO 3166 Trigram) | - | Astronomy |
| GEOS | Graphical Environment Operating System | - | Astronomy |
| GESTAPO | GEheime STAatsPOlizei (German Secret State Police) | - | Astronomy |
| GEV | Ground Effect Vehicle | - | Astronomy |
| GEV | Gigaelectron-volt | - | Astronomy |
| GF | French Guiana (ISO 3166 Digram) - Gigafarad | - | Astronomy |
| GFCI | Ground Fault Circuit Interruptor (aka GFI) | - | Astronomy |
| GFDL | GNU Free Documentation License | - | Astronomy |
| GFE | Girl Friend Experience (used In Escort Services) - Good Faith Estimate - Government Furnished Equipment | - | Astronomy |
| GFI | Ground Fault Interruptor (aka GFCI) | - | Astronomy |
| GFN | Global Footprint Network | - | Astronomy |
| GFY | Good For You Or Go Fuck Yourself | - | Astronomy |
| GG | Georgia (FIPS 10-4 Country Code) | - | Astronomy |
| GGP | General Game Playing | - | Astronomy |
| GH | Ghana (ISO 3166 Digram; FIPS 10-4 Country Code) - Gigahenry | - | Astronomy |
| GHA | Ghana (ISO 3166 Trigram) | - | Astronomy |
| GHB | Gamma-HydroxyButyrate | - | Astronomy |
| GHC | Ghanan Cedi (ISO 4217 Currency Code) | - | Astronomy |
| GI | Galvanised Iron - Gastro-Intestinal - General Issue -Gibraltar (ISO 3166 Digram; FIPS 10-4 Territory Code) -Government Issue | - | Astronomy |
| GI | Gibi | - | Astronomy |
| GIB | Gibraltar (ISO 3166 Trigram) | - | Astronomy |
| GIF | Graphics Interchange Format (pronounced Jif) | - | Astronomy |
| GIG | Global Information Grid | - | Astronomy |
| GIGO | Garbage In Garbage Out (computing) | - | Astronomy |
| GIMP | GNU Image Manipulation Program | - | Astronomy |
| GIN | Guinea (ISO 3166 Trigram) -Guidelines International Network | - | Astronomy |
| GINO | Godzilla In Name Only | - | Astronomy |
| GIP | Gibraltar Pound (ISO 4217 Currency Code) | - | Astronomy |
| GIS | Geographic Information System -Google Image Serach | - | Astronomy |
| GISS | General Impression Of Size And Shape - Goddard Institute For Space Studies | - | Astronomy |
| GJ | Gigajoule - Grenada (FIPS 10-4 Country Code) | - | Astronomy |
| GJD | Geocentric Julian Day | - | Astronomy |
| GK | Gigakelvin - Guernsey (FIPS 10-4 Territory Code) | - | Astronomy |
| GL | Galician Language (ISO 639-1 Code) | - | Astronomy |
| GL | Gigalitre -Graphics Language -Greenland (ISO 3166 Digram; FIPS 10-4 Territory Code) -Grenade Launcher | - | Astronomy |
| GLA | Scottish Gaelic Language (ISO 639-2 Code) | - | Astronomy |
| GLAAD | Gay And Lesbian Alliance Against Defamation | - | Astronomy |
| GLAC | General Ledger Accounting Code | - | Astronomy |
