OS

/ˌoʊ ˈɛs/

Proposed by a contributor, not yet supported by evidence.

Also seen as: OSes · OSs · OS's · ossa

Sense 1

Meaning · English

An Ordnance Survey map.

NounRegister: UK

Examples

We've got an OS of the Cuckmere area.

Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Sense 2

Meaning · English

Synonym of bone.

Noun

Examples

I was once, I remember, called to a Patient, who had received a violent Contuſion in his Tibia, by which the exterior Cutis was lacerated, ſo that there was a profuſe ſanguinary Diſcharge; and the interior Membranes were ſo divellicated, that the Os or Bone very plainly appeared through the Aperture

Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Sense 3

Meaning · English

An opening or entrance to a passage, particularly one at either end of the cervix, internal (to the uterus) or external (to the vagina).

Noun

Examples

The instrument closed, as seen in Fig. 1, is then passed along the finger to the os, in and through the cervix up to the fundus of the uterus, which may be determined both by the distance and the resistance to the broad rounded head of the Capiat.

Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Sense 4

Meaning · English

An osar or esker.

Noun

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Common questions

What does “OS” mean?

An Ordnance Survey map.

Is “OS” formal or informal?

OS is generally UK.