OS

OS, O.S., Os, O's, or os may refer to:

Computing

• Operating system, system software that manages computer hardware and software resources
• Open source (disambiguation)
• OpenStack, a software platform for cloud computing

Medicine

• os or ostium, a mouth or mouth-like opening
  • external os, the external orifice of the uterus
  • internal os, the internal orifice of the uterus
  • per os, meaning "ingestion by mouth"
  • os or ostium, the opening of a coronary artery
• O.S. or OS, oculus sinister, meaning "left eye" in general ophthalmologic or optometric usage, particularly in eyeglass prescriptions (deprecated abbreviation)
• Ohtahara syndrome, a brain disorder
• Overall survival rate, a cancer survival statistic
• Oneiroid syndrome, a dreamlike fantastic delusional state

People

• Alexander Os (born 1980), a Norwegian biathlete
• Os du Randt (born 1972), a South African rugby player
• Os Guinness (born 1941), an English author and social critic
• For people named van Os see Van Os

Places

Norway

• Os Municipality (Innlandet), a municipality in Innlandet county, Norway
• Os Municipality (Hordaland), a former municipality in the old Hordaland county, Norway
• Os i Østerdalen, a village within Os Municipality in Innlandet county, Norway
• Os, Østfold, a parish in Rakkestad Municipality in Østfold county, Norway
• Os Church, a name for several churches in Norway

Poland

• Oś, Kluczbork County, a village in Kluczbork County, Opole Voivodeship, Poland
• Osiedle (Os.), a Polish term used for housing subdivisions in Poland

Other places

• Os, Värnamo, a village in Värnamo Municipality, Småland province, Sweden
• OS, ICAO code for airports in Syria
• OS, WMO country code for Austria

Religion

• Ōs, an Old English word denoting a god in Anglo-Saxon paganism, related to æsir
• O.S., Order of Santiago, a Spanish order dedicated to St James the Greater
• O.S., Order of Sikatuna, the national order of diplomatic merit of the Philippines

Science

• Ocean Science (journal), an oceanographic journal
• Osmium, symbol Os, a chemical element

Businesses

• Ordnance Survey, national mapping agency of Great Britain
• Austrian Airlines (IATA code OS based on its original name: Österreichische Luftverkehrs AG)
• O.S. Engines, a Japanese manufacturer of model aircraft engines

Sport

• Ohio State Buckeyes, a group of collegiate teams representing The Ohio State University
• Os TF, a sports club in Os, Norway
• On-sight climbing, an ascent of a rock climbing route on the first attempt
• Baltimore Orioles, an American baseball team nicknamed "O's"
• Leyton Orient, an English football (soccer) team nicknamed "O's"

Titles

• Ordinary seaman, an unlicensed member of the deck department of a merchant ship
• Ordnance sergeant, an enlisted rank in the U.S. and Confederate armies during the American Civil War era
• Old Shirburnian, used by alumni of Sherborne School
• Old Stonyhurst, used by alumni of Stonyhurst College

Other uses

• Esker, also os, a long, winding ridge of sand and gravel in (formerly) glaciated regions
• "Os" (Fringe), an episode of the television show Fringe
• Ōs (rune) (ᚩ), a rune of the Anglo-Saxon fuþorc
• Old Style (O.S.) date, indicating use of an earlier calendar (in Anglophone countries, the Julian Calendar), as opposed to "N.S." (new style), usually indicating use of the Gregorian Calendar
• Ossetic language (ISO 639-1 abbreviation OS)

See also

• 0S (disambiguation)
• ÖS (disambiguation)
• Oz (disambiguation)