(computing) An instruction or operation that has no effect; a null operation.

(LGBT, of a transgender or transsexual person) Having chosen not to undergo sex reassignment surgery.

(LGBT) A transgender or transsexual person who has chosen not to undergo sex reassignment surgery.

(music, abbreviation) Opus. / (law) Abbreviation of opinion.

(Cornwall) alley or narrow passage e.g. Tonkin's Ope

(Midwest) an exclamation of surprise; oops

(now dialectal or poetic) Open.

(archaic, transitive, intransitive) To open.

plural of op

(informal) operations / (Internet, IRC) operator status