Definition: (sport) the mistake of occupying an illegal position on the playing field (in football, soccer, ice hockey, field hockey, etc.)
Definition: An offside play.
Definition: illegally beyond a prescribed line or area or ahead of the ball or puck; "the touchdown was nullified because the left tackle was offside"
Definition: In an illegal position ahead of the ball, puck, etc.
Definition: illegally in advance of the ball or puck