OS
bone, os
(noun) rigid connective tissue that makes up the skeleton of vertebrates
os
(noun) a mouth or mouthlike opening
osmium, Os, atomic number
(noun) a hard brittle blue-grey or blue-black metallic element that is one of the platinum metals; the heaviest metal known
Source: WordNet® 3.1
Proper noun
OS (plural er-noun)
(sports) Abbreviation of Owen Sound.
Adjective
OS (not comparable)
Abbreviation of outsize (clothes for large people)
Abbreviation of Old Style; a term used in English language historical studies to indicate that a date conforms to the Julian calendar instead of the modern Gregorian calendar
(screenwriting) Abbreviation of Offscreen; indicates a line of dialogue is spoken by someone not visible onscreen
Noun
OS (plural OSes or OSs)
(UK) an Ordnance Survey map.
(software) Initialism of operating system.
Anagrams
• S&O, SO, So, So., s.o., s/o, so
Etymology 1
Noun
os (plural ossa)
(rare, medicine) Bone.
Usage notes
Only used by doctors and surgeons when practising. Not used by medical laypeople.
Etymology 2
Noun
os (plural ora)
(rare) A mouth; an opening.
In particular, either end of the cervix, internal (to the uterus) or external (to the vagina).
Etymology 3
Noun
os
An osar or esker.
Etymology 4
Noun
os
(rare) plural of o. More commonly oes or o's.
Anagrams
• S&O, SO, So, So., s.o., s/o, so
Noun
Os
plural of O
Anagrams
• S&O, SO, So, So., s.o., s/o, so
Source: Wiktionary