| Acronym | Definition |
|---|
| HI | Hawaii (US postal abbreviation) |
| HI | Holiday Inn |
| HI | Health Insurance |
| HI | Hindi (linguistics) |
| HI | Home Improvement |
| HI | Handicap International |
| HI | Head Injury |
| HI | High Intensity (carbon) |
| HI | Health International |
| HI | Hydraulic Institute |
| HI | HelpAge International |
| HI | Hostelling International |
| HI | Harris Interactive |
| HI | Hospital Insurance |
| HI | Humanitarian Intervention |
| HI | Health Informatics (various organizations) |
| HI | High Impedance |
| HI | Heart Institute |
| HI | Human Impact (index) |
| HI | Hearing Impairment |
| HI | Haemophilus Influenzae (bacteria) |
| HI | Harvest Index |
| HI | Heifer International |
| HI | Hardware Item |
| HI | Human Interactions |
| HI | Hemagglutination Inhibition |
| HI | Hostile Intent (gaming, Half-Life Modification) |
| HI | Heartland Institute (Chicago, IL) |
| HI | Hudson Institute |
| HI | Hydrogen Index |
| HI | Heat Insulated |
| HI | Head Guard (lifeguarding) |
| HI | Hasbro Interactive |
| HI | Hazard Index |
| HI | Hurley International (clothing company) |
| HI | Horizontal Integration |
| HI | Historiographical Institute (University of Tokyo; Japan) |
| HI | Heritage India (festival) |
| HI | Humorous Interpretation |
| HI | Hydriodic Acid |
| HI | Household International, Inc. (stock symbol) |
| HI | Heliospheric Imager |
| HI | High Inquisitor (Robert Jordan's Wheel of Time) |
| HI | Homicidal Ideation |
| HI | Height Indicator |
| HI | Hearing International |
| HI | Hospital Income (health insurance) |
| HI | Height of Instrument (surveying) |
| HI | Hochspannungsinstitut (German: High Voltage Institute) |
| HI | Harmony Incorporated (International Organization of Women's Barbershop Singers) |
| HI | Horizontal Indicator (aviation) |
| HI | Handover Initiation |
| HI | Heavy Inspection |
| HI | Herramientas Industriales (Spanish: hardware industry) |
| HI | Headington Institute (Pasadena, CA) |
| HI | Hertzian Indentation |
| HI | Hazelwood Initiative, Inc. (Pittsburgh, PA) |
| HI | Hollingshead International |
| HI | Hovedstadens Jernbane-Idræt |
| HI | Horizontal Inverval |
| HI | Hochschulverband für Informationswissenschaft eV |
| HI | High Nuc in Backhaul Check (airfare construction) |