I. ˈō noun
( plural o's or os ˈōz)
Usage: often capitalized, often attributive
1.
a. : the 15th letter of the English alphabet
b. : an instance of this letter printed, written, or otherwise represented
c. : a speech counterpart of orthographic o (as long o in code, short o in cod, or o in cord )
2. : a printer's type, a stamp, or some other instrument for reproducing the letter o
3. : someone or something arbitrarily or conveniently designated o especially as the 14th or when j is used for the 10th the 15th in order or class
4. : something having the shape of the capital letter O
made an enthusiastic O with his thumb and forefinger — John Dos Passos
the Roman girl's eyes widened, her mouth formed an O — F.V.W.Mason
especially : zero
wrote a couple of O's
II.
Usage: usually capitalized
variant of oh
III. abbreviation
Usage: often capitalized
1. object
2. oblast
3. observation; observer
4. occident; occidental
5. ocean
6.
[Latin octarius ]
pint
7. October
8.
[Latin oculus ]
eye
9. off
10. office; officer
11. official
12. ohm
13. oil
14. old
15. only
16. opening
17. operation
18.
[Latin optimus ]
best
19. order
20.
[Latin ordinis ]
of the order of
21.
[Latin ordo ]
order
22. ordnance
23. oriental
24. original
25.
[Latin os ]
bone
26. out
27. outfield
28. outlet
29. over
30. overcast
31. owner
IV. symbol
Usage: capitalized
1. octavo
2. oxygen