| Abbreviation | Definition |
|---|---|
| HAD | HaloAcid Dehalogenase |
| HAL | Heat, Air, Liquid |
| HAND | Humanitarian Aid Network For Distribution |
| HAP | High Age Profile |
| HAP | Holographic Assistance Program |
| HASL | Hybrid Anaerobic Solid Liquid |
| HAT | Hypoxanthine, Aminopterin, Thymidine |
| HATU | Hexafluorophosphate Azabenztriazole Tetramethyl Uronium |
| HAZCHEM | HAZardous CHEMical |
| HAZMAT | Hazardous Materials |
| HB | H Bonding |
| HB | Hydrogen Bomb |
| HB | Hydrogen Bond |
| HB | Hydrogen Bonded |
| HBC | HexaBenzo-Coronene |
| HBCD | Hexabromocyclododecane |
| HBCD | Highly Branched Cyclic Dextrin |
| HBCS | Hearing Balance and Chemical Senses |
| HBD | 2-HydroxyButyrate Dehydrogenase |
| HBD | Hydrogen Bond Donor |