Main definitions of os in English

: os1os2

os1

noun

Anatomy
  • A bone (used chiefly in Latin names of individual bones, e.g., os trapezium)

    ossa
    • ‘In this group, the cortex of the os sacrum was destroyed and had a spongelike rather than compact appearance.’
    • ‘Besides this unambiguous distinguishing character, a second, derived character, exists which is particular to the Carnivora: in the wrist the joint bones, scaphoid, lunate, and os centrale, are fused.’

Origin

Latin.

Main definitions of os in English

: os1os2

os2

noun

Anatomy
  • An opening or entrance to a passage, especially one at either end of the cervix of the uterus.

    ora
    • ‘The internal os closes by 3 days, the external os by 3 weeks.’
    • ‘The distance between the internal and external os was measured both as a straight line and also as a curved line along the endocervical canal.’

Origin

Mid 18th century: from Latin os mouth.

Main definitions of os in English

: os1os2

Os

  • The chemical element osmium.

Main definitions of os in English

: os1os2

OS

  • 1(in calculating dates) Old Style.

  • 2Computing
    Operating system.

  • 3Ordinary Seaman.

  • 4(in the UK) Ordnance Survey.

  • 5(as a size of clothing) outsize.

  • 6Out of stock.

  • 7Overseas.