O Very Common

a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust

the 15th letter of the Roman alphabet

the blood group whose red cells carry neither the A nor B antigens

"people with type O blood are universal donors"

The name of the Latin-script letter O .

Operator

A blood type that lacks A or B antigens and may only receive transfusions of similar type O blood, but may donate to all (neglecting Rh factor). Synonym: universal donor.

American Library Association abbreviation of octavo, a book size (20-25 cm).

Over

Abbreviation of morally offensive. (film classification of the National Legion of Decency)

The fifteenth letter of the English alphabet, called o and written in the Latin script.

The ordinal number fifteenth, derived from this letter of the English alphabet, called o and written in the Latin script.

alternative form of O (vocative particle)

The English vocative particle, used for direct address.

Alternative form of oh

Alternative form of of

A Korean surname, from Korean, the English form of a surname very common in Korea. (오 (O), hanja: 伍, 吳).

Alternative form of E