os Meaning, Definition & Usage

  1. noun a mouth or mouthlike opening
  2. noun a hard brittle blue-grey or blue-black metallic element that is one of the platinum metals; the heaviest metal known
    osmium; atomic number 76.
  3. noun (computer science) software that controls the execution of computer programs and may provide various services
    operating system.
  4. noun the left eye
    oculus sinister.
  5. noun rigid connective tissue that makes up the skeleton of vertebrates
    bone.
  6. noun a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust
    O; oxygen; atomic number 8.
  7. noun the 15th letter of the Roman alphabet
    o.
  8. noun the blood group whose red cells carry neither the A nor B antigens
    group O; type O; O.
    • people with type O blood are universal donors

WordNet

Os noun
Etymology
L.
Wordforms
plural Ossa
Definitions
  1. A bone.
Os noun
Etymology
L.
Wordforms
plural Ora
Definitions
  1. A mouth; an opening; an entrance.
Os noun
Etymology
Sw. ås ridge, chain of hills, pl. åsar.
Wordforms
plural Osar
Definitions
  1. (Geol.) One of the ridges of sand or gravel found in Sweden, etc., supposed by some to be of marine origin, but probably formed by subglacial waters. The osar are similar to the kames of Scotland and the eschars of Ireland. See Eschar.

Webster 1913