- Sports. illegally beyond a prescribed line or area or in advance of the ball or puck at the beginning of or during play or a play: The touchdown was nullified because the offensive left tackle was offside.
- with or in doubtful propriety or taste; risqué: an offside joke.
- sport (in football, hockey, etc) in a position illegally ahead of the ball or puck when it is played, usually when within one’s opponents’ half or the attacking zone
- the offside mainly British
- the side of a vehicle nearest the centre of the road (in Britain, the right side)
- (as modifier)the offside passenger door
also off-side, 1867, in various sporting senses, originally in English football; from off + side (n.).