sort by Rank | Alpha
| Possible Meanings | Rank |
| Onion River Sports | ***** |
| Oil Recovery System | ***** |
| Of Research Services | **** |
| Office of Retirement Services | **** |
| Oak Ridge Schools | **** |
| Octopole Reaction System | **** |
| Overseas Research Scholarships | **** |
| Open Research Society | **** |
| Online Research System | **** |
| Overseas Research Students | **** |
| Official Relay Station | **** |
| Observational Rating Scale | **** |
| Of Rehabilitation Services | **** |
| Orthopaedic Research Societies | **** |
| Order Request System | **** |
| Office of Rehabilitation Services | **** |
| Or Operating Requirements | **** |
| Other Reporting System | **** |
| Organizational Research Services | *** |
| Oromiya Regional State | *** |
| Online Record Search | *** |
| Online Retrieval System | *** |
| Open Research System | *** |
| Office of Regulatory Services | *** |
| Online Recovery Service | *** |
| Office of Research and Standards | *** |
| Oral Rehydration Solutions | *** |
| Of Rehydration Salts | *** |
| Operational Reporting System | *** |
| Operational Research Systems | *** |
| Of Radiation Safety | *** |
| Overseas Research Scholarship | *** |
| Online Registration System | *** |
| Outcome Rating Scale | *** |
| Office of Recreation and Sport | *** |
| Of Regulatory Staff | *** |
| Orlando Riva Sound | *** |
| Overseas Research Studentship | *** |
| Otel Rezervasyon Sistemi | *** |
| Optical Remote Sensing | *** |
| Office of Recovery Services | *** |
| Online Response System | *** |
| Oak Ridge School (Eagan, MN) | *** |
| Oregon Revised Statues | *** |
| O Ring Straight | *** |
| Online Recovery Support | *** |
| Office of Retirement Systems | *** |
| Operations Research Society | *** |
| Online Radio Station | *** |
| Opinion Research Services | *** |
| Orthopedic Research Society | *** |
| Optical Reference Systems | *** |
| Office for Research and Statistics | *** |
| Octagon Risk Services | *** |
| Orbital Refueling System | *** |
| Optical Redshift Survey | *** |
| Operational Radiation Safety | *** |
| Orthopedic Rehab Specialists | *** |
| Online Reservation System | *** |
| Optical Replica Synthesizer | *** |
| Oral Reading Study | *** |
| Office of Road Safety | *** |
| Old Red Sandstone | *** |
| Outer Rim Scouts | *** |
| Ongoing Resourcing Scheme | *** |
| Ordinary Registered Shares | *** |
| Oil Renewal System | *** |
| Ongoing Rehabilitation and Support | *** |
| Office Research Service | *** |
| Object Recognition Systems | *** |
| OsteoArthritis Research Society | *** |
| Office of Radiation Safety | ** |
| Operational Research Services | ** |
| G)-oral rehydration solution | ** |
| objective rigidity score | ** |
| ongoing rehabilitation setting | ** |
| optical reflectance spectroscopy | ** |
| oral rehydrating solution | ** |
| oral rehydrating solutions | ** |
| oral rehydration serum | ** |
| oral replacement solution | ** |
| orthogonal regression slope | ** |
| osteoclastic resorption surface | ** |
| osteoclastic resorption surfaces | ** |
| Otorhinolarygological Research Society | ** |
| Outer root sheath | ** |
| ovarian retention syndrome | ** |
| oxygen radical scavangers | ** |
| oxygen reactive species | ** |
| Ovarian Remnant Syndrome | ** |
| Opera Reservation System | ** |
| 80--oropharyngeal syndrome | ** |
| Optical Record Systems | ** |
| Orbiting Research Satellite | ** |
| Object Recognition Subsystem | ** |
| Head-orienting responses | ** |
| open venous reservoir system | ** |
| oral re-hydration solution | ** |
| oral rehydration salt solution | ** |
| oral rehydration salt solutions | ** |
| oral rehydration salts solutions | ** |
| oral rehydration solutions therapy | ** |
| outer root sheath cells | ** |
| Optometric Retina Society | ** |
| Office of Rehabilitative Services | ** |
| Online Routing System | ** |
| Operations Room Supervisor | ** |
| Office of Refugee Services | ** |
| original rap staff | ** |
| Occupational Radiation Safety | ** |
| Oral Rehydration Saline | ** |
| Organic Root Stimulator | ** |
| Octapole Reaction System | ** |
| Org Research Society | ** |
| Oral Rehydratation Salt | ** |
| olfactory receptor proteins | ** |
| Or Other Survey | ** |
| Ownership Reporting System | ** |
| MEASURE--Odds ratios | ** |
| Ohio Response System | ** |
| origin-enriched sequences | ** |
| Ortadogu Rulman Sanayi | ** |
| Opportunity and Referral Service | ** |
| Organization of Residence Students | ** |
| Office of Regulation Services | ** |
| Oak Ridge Solutions | ** |
| Operational Requirement Specification | ** |
| Occupant Restraint System | ** |
| Opiliones Recording Scheme | ** |
| On the Right Shows | ** |
| Operating Reliability Subcommittee | ** |
| Obligated Reserve Service | ** |
| One Room Schoolhouse | ** |
| Office of Regional Services | ** |
| Operations Research Spektrum | ** |
| Optical Radiation Safety | ** |
| Organizational Relationships Scale | ** |
| Object Replication Service | * |
| Online Resource Scheduler | * |
| Oregon Repertory Singers | * |
| Orientation Reservation System | * |
| Octahedral Research Satellite | * |
| Office for Research Safety | * |
| Operations Reporting System | * |
| Office of Revenue Systems | * |
| ohio river survey | * |
| Operational Revision Status | * |
| Ontario Research Sites | * |
| Object Registration Services | * |
| Offense Reporting System | * |
| Olfactory Reference Syndrome | * |
| Operational Readiness Survey | * |
| Oscar Robertson Solutions | * |
| Otter Risk Solutions | * |
| Oxygen Radical Scavengers | * |
| Operations Research Software | * |
| Oceanographic Research Ship | * |
| Offset Radiation Source | * |
| Ohio River Sweep | * |
| Operational Requirement Statement | * |
| Operational Risk Services | * |
| Ordnance Related Scrap | * |
| Ortadodu Rulman Sanayy | * |
| Oak Ridge Shaft | * |
| Oceanography Related Software | * |
| Office for Remote Sensing | * |
| Office of Registrar and Student | * |
| Office of Research and Sponsored | * |
| Office of the Registrar and Studies | * |
| Onca Ray Solarlink | * |
| Online Resources for Sustainabil | * |
| Online Retrieveal System | * |
| Online Rulebooks and Schedules | * |
| Openings in Rock or Soil | * |
| Opportunity-Rich Segment | * |
| Optilabs Recreational Spectacles | * |
| Optimal Response to a Shift | * |
| Optional Rehabilitation Services | * |
| Orthopaedic Research Society R.O.C. (Taiwan) | * |
| Oyster River Schools | * |