| Abbreviation | Definition |
|---|---|
| HIU | Headset Interface Unit |
| HIV | Human Immuno-Deficiency Virus |
| HIV | Human Immunodeficiency Virus |
| HIV | Helium Isolation Valve |
| HIVE | Hierarchy Of International Vengeance And Extermination |
| HJD | Helicentric Julian Date |
| HK | House Keeper |
| HKC | Human Kidney Cell |
| HKT | Hong Kong Tailor |
| HL | Hearing loss |
| HL | Heart and Lungs |
| HL | Hepatic Lipase |
| HL | Hepatic Lipidosis |
| HL | Hearing Level |
| HL | Head Lice |
| HL | Hair Loss |
| HL | Hyperpigmented Lesions |
| HL | Hydrogen Line |
| HL-A | Human Leukocyte Associated antigens (HL-A matching for BMT) |
| HLA | High Level Assembly |
| HLA | Heart, Lungs, Abdomen |
| HLA | Human Leukocyte Antigen |
| HLA | Hyperbaric Lighting Assembly |
| HLA | Hydraulic Launch Assist |
| HLA | Heavy Load Assessment |
| HLA | Horizontal Line Array |
| HLA | Helicopter Landing Area |
| HLA | Heavy Lift Aircraft |
| HLA | Harvest Limit Area |
| HLAL | High Level Assembler Language |
| HLAR | High-memory Load Access Rights |
| HLAR | Horizontal Low-Altitude Release |
| HLAS | Handbook of Latin American Studies |
| HLB | Hornsey Local Board |
| HLBS | Heart, Lung, Blood, and Sleep disorder |
| HLC | Humanitarian Law Commission (Red Cross) |
| HLC | Human Lactic Commensals |
| HLC | Hair Loss Control |
| HLC | Historic Landmark Commission |
| HLC | Healthy Lawn Care |
| HLC | Heavy Lift Capability |
| HLCC | High Level Consultative Commission |
| HLCC | High Level Coordination Committee |
| HLCP | High Level Committee of Programmes |
| HLCP | Healthy Lawn Care Program |
| HLDC | High Level Data Link Control |
| HLDS | Hydrogen Leak Detection System |
| HLF | Humanitarian Law Commission |
| HLK | Heart, liver, kidney |
| HLL | High Level Link |