An Encylopedia Britannica Company

o

o noun
or O /ˈoʊ/
plural o's or os or O's or Os /ˈoʊz/
o
noun
or O /ˈoʊ/
plural o's or os or O's or Os /ˈoʊz/
Britannica Dictionary definition of O
: the 15th letter of the English alphabet
[count]
[noncount]
[count] : the number zero used in speech when referring to numbers
[count] used as a mark at the end of a letter, an e-mail, etc., to represent a hug