(politics) Negative information retrieved about a candidate's opponent in an election for use in campaigning.

A large, defended Iron Age settlement associated with the Celtic La Tène culture.

(idiomatic) A person who holds a position in an organization that corresponds to that held by another person in another organization; a counterpart

present participle of op

(Internet) The promotion of an IRC user to operator status.

simple past tense and past participle of op

A period of time in which suitable action can achieve success.

plural of window of opportunity

A side, party (e.g. a team or armed force) seen as adversary, enemy etc. opposite one (or more) other(s), as in a battle or team sports competition.

plural of opposite number