| Acronym | Meaning |
| GSO | General Spin Orbital |
| GSR | Gunshot Residue |
| GSZ | Green-Sellin-Zachor Model Potential (for Atoms) |
| GT | Gelfand-Tsetlin Basis Function |
| GT | Gas Turbine |
| GTA | Gas Tungsten Arc Welding |
| GTAW | Gas-tungsten Arc Welding |
| GTCP | Global Tropospheric Chemistry Program |
| GTDA | Generalized Tamm-Dancoff Approximation |
| GTE | Global Tropospheric Experiment |
| GTF | Gaussian-type (wave) Function |
| GTG | Gaussian-type Geminal |
| GTN | Global Trend Network |
| GTO | Gaussian-type Orbital |
| GTP | Group-transfer Polymerization |
| GTP | Guanosine 5'-triphosphate |
| GTSP | Global Tracer Scientific Panel |
| GTSSP | Global Temperature And Salinity Pilot Program |
| GTT | Glucose Tolerance Test |
| GUE | Gaussian Unitary Ensemble (of Random Matrixes In Quantum-transport Studies) |
| GUGA | Graphical Unitary Group Approach |
| GUI | Graphical User Interface |
| GUS | Groundwater Ubiquity Score |
| GUVI | Global Ultraviolet Imager |
| GVB | Generalized Valence Bond |
| GVB-CI | Generalized Valence Bond-configuration Interaction (wave Function) |
| GVB-INIT | Generalized Valence Bond-initial (guess Wave Function) |
| GVB-MDSA | Generalized Valence Bond-molecular Dynamics Simulated Annealing |
| GVB-PP | Generalized Valence Bond-perfect Pairing (wave Function) |
| GVBD | Germinal Vesicle Breakdown |
| GVDW | Generalized Van Der Waals (a Free-energy D.-functional Theory) |
| GVFF | Generalized Valence Force Field |
| GVHD | Graft Versus Host Disease |
| GVP | Gasoline Vapor Pressure |
| GVVPT | Generalized Van Vleck Perturbation Theory |
| GW | One-particle Green Function(g)-screened Coulomb Interaction(w) |
| GW-PG | Gaussian-weighted Planar Grid (method In Calcns. Of Electron-momentum Distributions) |
| GWB | Gopinathan-Whitehead-Bogdanovic (Fermi-hole Parameters) |
| GWD | Gaussian Wave Packet Dynamics |
| GWDR | Ground Water Disinfection Rule |
| GWF | Generalized Wannier Function |
| GWF | Global Warming Factor |
| GWKB | Generalized Wentzel-Kramers-Brillouin |
| GWM | Groundwater Monitoring |
| GWP | Gaussian Wave Packet |
| GWP | Global Warming Potential(s) |
| GWPC | Ground Water Protection Council |
| GWPM | Gaussian Wave-packet Method |
| GWPS | Groundwater Protection Standard |
| GWPS | Groundwater Protection Strategy |