| Abbreviation | Definition |
|---|---|
| HRSG | Heat Recovery Steam Generator |
| HRT | High Resolution Thermometer |
| Hs | Hassium |
| HS | Hidden States |
| HSC | Hydrogen Synthesiser Cannon |
| HSCL | Himadri Speciality Chemical Ltd |
| HSGO | High Sulphur Gas Oil |
| HSHA | Hypertonic Saline Hyaluronic Acid |
| HSM | High Salt Medium |
| HSN | Hehre, Shusterman, and Nelson |
| HSS | Heat Stable Salt |
| HSV | High Shear Viscosity |
| HT | Heat Transport |
| HT | Heat Treatment |
| HTC | Heat Transfer Coefficient |
| HTFA | Hydrogenated Tallow Fatty Acid |
| HTFT | High-temperature Fischer–Tropsch process |
| HTG | High Temperature Generator |
| HTGR | High Temperature Gas Reactor |
| HTH | High Test Hypochlorite |