| Term | Definition | Contributor | Modified |
|---|---|---|---|
| HardXrays | Photons with a wavelength range: 0.001 to 0.1nm and an energy range of 12 keV to 120 keV | Ryan McGranaghan | 2023.04.16 |
| Hardystonite | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Hare and hounds | No definition provided | Christopher Rauch | 2023.12.01 |
| Harelip | No definition provided | Christopher Rauch | 2023.12.01 |
| Harelip’ | No definition provided | Christopher Rauch | 2023.12.01 |
| Harem | No definition provided | Christopher Rauch | 2023.12.01 |
| Hares | No definition provided | Christopher Rauch | 2023.12.01 |
| Hare’s Hill, Va., Battle of, 1865 | No definition provided | Christopher Rauch | 2023.12.01 |
| Harkerite | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Harlem Heights, Battle of, 1776 | No definition provided | Christopher Rauch | 2023.12.01 |
| Harlequin | No definition provided | Christopher Rauch | 2023.12.01 |
| Harmonia (Minor planet) | No definition provided | Christopher Rauch | 2023.12.01 |
| harmonic | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Harmonica (Musical glasses) | No definition provided | Christopher Rauch | 2023.12.01 |
| Harmonic analysis | No definition provided | Christopher Rauch | 2023.12.01 |
| Harmonicon, Chemical | No definition provided | Christopher Rauch | 2023.12.01 |
| Harmonie-gesellschaft | No definition provided | Christopher Rauch | 2023.12.01 |
| Harmonists | No definition provided | Christopher Rauch | 2023.12.01 |
| Harmonium | No definition provided | Christopher Rauch | 2023.12.01 |
| Harmonometer (Mechanical musical instrument) | No definition provided | Christopher Rauch | 2023.12.01 |