| Abbreviation | Definition |
|---|---|
| GTO | Gas Tube Only |
| GUK | Guanylate Kinase |
| GVL | gamma valeroactone |
| GVS | Galvanic Vestibular Stimulation |
| GWP | General Work Permit |
| H | Hydrogen |
| H20 | Water |
| H2CO3 | Carbonic Acid |
| H2O2 | Hydrogen Peroxide |
| H2S | Hydrogen Sulfide |
| H2SO4 | Sulfuric acid (not an acronym) |
| H2SO4 | Tetraoxosulphate (vi)acid |
| H9O | Nine Hydrogen and one Oxygen |
| HA | Hyaluronic Acid |
| HAA | Haloacedic Acid A |
| HAA | HaloAcetic Acid |
| HAA | Haloacetic Acid And |
| HAAS | Houston Area Acid Staining |
| HAB | Hyaluronic Acid Binding |
| HAc | acetic acid |