sort by Rank | Alpha
| Possible Meanings | Rank |
| Opportunities Abroad Program | ***** |
| Over Age Players | **** |
| Organic Action Plan | **** |
| Ownership Assistance Program | **** |
| Omnibus Autism Proceeding | **** |
| Old Age Provision | **** |
| Outside Air Pressure | **** |
| Other Academic Position | **** |
| Old Age Pensions | **** |
| Oceans Action Plan | **** |
| Orthopaedic Associates of Portland | **** |
| Outdoor Adventure Program | **** |
| Options Assessment Panel | **** |
| Open Agility Preferred | *** |
| Open Access Period | *** |
| Old Age Pensioners | *** |
| Office Automation Program | *** |
| Office of the Assistant to the President | *** |
| Office of Academic Programs | *** |
| Off Axis Parabola | *** |
| Office for Asia and the Pacific | *** |
| Over Aged Players | *** |
| Optically Active Pigments | *** |
| Office of Antimicrobial Products | *** |
| Optical Array Probe | *** |
| Offer Approval Process | *** |
| Outreach Admissions and Placement | *** |
| Off Axis Parabolic | *** |
| Operation Action Packed | *** |
| Olympic Athlete Program | *** |
| Osaka Amenity Park | *** |
| Office of Administrative Proceedings | *** |
| Ohio Abortion Providers | *** |
| Outcomes After Pregnancy | *** |
| Oregon Aviation Plan | *** |
| occiput anterior position | ** |
| of action potential | ** |
| oncogene activated production | ** |
| ophthalmic arterial pressure | ** |
| opinions about people | ** |
| oral anticoagulant prophylaxis | ** |
| ordinary ambulance personnel | ** |
| orthopedic antithrombotic prophylaxis | ** |
| Oscillatory after-potentials | ** |
| osseous alkaline phosphatase | ** |
| overdrive atrial pacing | ** |
| Outside Awareness Port | ** |
| Oregon Asthma Program | ** |
| ophthalmic artery systolic pressure | ** |
| opsonic activity of plasma | ** |
| Ove Arup and Partners | ** |
| Ohio Association of Parliamentarians | ** |
| Opticians Association of Pennsylvania | ** |
| Ocean Action Plan | ** |
| Open Architecture Program | ** |
| Old Age Persons | ** |
| of intramembrane particles | ** |
| of intramembranous particles | ** |
| of small particles | ** |
| Office of Atoms for Peace | ** |
| Office of Aerospace | ** |
| Office of Adult Probation | ** |
| Ophthalmic Artery Pressure | ** |
| Office of Acquisition Policy | ** |
| Optic Axial Plane | ** |
| Office Application Proficiency | ** |
| Offences Against the Person | ** |
| Office of Advanced Planning | ** |
| Organic Advisory Programme | ** |
| Old Aged Players | ** |
| Overhead Annunciator Panel | ** |
| Off Axis Paraboloids | ** |
| Overseas Academic Program | ** |
| Operator Adaptation Packages | ** |
| Open Access Publications | ** |
| Orthopedic Allied Professional | ** |
| Outgoing Active and Positive | ** |
| Optometric Association of the Philippines | ** |
| Org Arts Projects | ** |
| Organizing Apprenticeship Project | ** |
| Olympic Athlete Programme | ** |
| Oyster Advisory Panel | ** |
| Odessa Astronomical Publications | ** |
| Operational Assistance Program | ** |
| Orange Album Project | ** |
| Old Aged Pensioners | ** |
| Office of Attending Physician | * |
| Older Aged Players | * |
| Operating Assistance Program | * |
| Optical Axial Plane | * |
| Over the Air Programming | * |
| Observed to Apparent | * |
| Office Automation Planning | * |
| Office of Antarctic Programs | * |
| Online Analytical Processing | * |
| Organization Alignment Process | * |
| Oxygen at Atmospheric Pressure | * |
| Office of Adolescent Pregnancy | * |
| Offset Aiming Point | * |
| Over Anxious Patient | * |
| Opci Anksiozni Poremecaj | * |
| Operator Assistance Program | * |
| Operational Aeromedical Problems | * |
| Operating and Assurance Program | * |
| Outdoor Action Program | * |
| Offshore Asset Protection | * |
| Operating and Assurance Plan | * |
| Oppimiskeskus Aurora Press | * |
| Obstetric Anesthesia and Perinat | * |
| Oceania Atlantis Project | * |
| OcTanos Atlßnticos y Pacfficos | * |
| office assignment problem | * |
| Office of Acquisition and Proper | * |
| Office of Agency Programs | * |
| Office of Atmospheric | * |
| Office of Atmospheric Programs | * |
| Old Art Publishing | * |
| Online Auctions on in Progress | * |
| Original Acrylic Paintings | * |
| Original Approved Planting | * |
| Osservatorio Astronomico di Pado | * |
| Other Agent of a Party | * |
| Overlying Area to be Protected | * |