sort by Rank | Alpha
| Possible Meanings | Rank |
| House Automated Payment System | **** |
| Heating and Plumbing Services | **** |
| Houston Area Power Strokes | **** |
| Human Anatomy Physiology Society | **** |
| Human Anatomy and Physiology Society | *** |
| High Altitude Platform Stations | *** |
| Hunter Area Pathology Service | *** |
| Haight Ashbury Psychological Services | *** |
| Homeless Animals Protection Society | *** |
| Hospital Annual Planning Submission | *** |
| Houston Area Parkinson Society | *** |
| Highly Available Publish Subscribe | *** |
| High Altitude Platform System | *** |
| HARDI ASIC Prototyping System | *** |
| Homestudies and Adoption Placement Services | *** |
| Hazardous Air Pollutants Solvent | *** |
| HIV AIDS Partnership Scheme | *** |
| Hepatic arterial perfusion scintigraphy | ** |
| hepatic artery perfusion scintigraphy | ** |
| high anal pressure syndrome | ** |
| hyperplastic-adenomatous polyposis syndrome | ** |
| Humanitarian Assistance and Peace and Security | ** |
| Hospital Anxiety and Depression Scale | ** |
| hydroxyapatite coatings applied by plasma-spraying | ** |
| hook-associated axial proteins | ** |
| Human Anatomy and Physiological Society | ** |
| Homestudies and Placement Services | ** |
| Huddersfield Astronomical and Philosophical Society | ** |
| Hybrid Algae Production System | ** |
| Human and Personal Services | ** |
| Histories and Addresses of Philosophical Societies | ** |
| Hydro Accumulation Power Station | ** |
| Historic Aircraft Preservation Society | ** |
| High Altitude Platform Services | * |
| HIV and Alcohol Prevention in Schools | * |
| Highly Automated Parallel Sorting | * |
| Hellenic American Professional Society | * |
| Hemet Area Polio Survivors | * |
| Hadley Angling and Preservation Society | * |
| Harrow Adult Placement Service | * |
| Health and Ageing Postgraduate Studies | * |
| Help the Aged Police Scheme | * |
| Hertfordshire Advanced Passenger System | * |
| High Altitude Profiling System | * |
| Housing Assistance Program for Seniors | * |
| Humanities Association of Postgraduate Students | * |
| Hurricane Analysis and Processing System | * |
| Help Author a Progressive Story | * |