adverb (or adjective)
1. : illegally in advance of the ball or puck: as
a. : beyond or across the line of scrimmage in football before the ball is snapped
b. : in the opponent's territory in field hockey or soccer in advance of a teammate having the ball when less than two opponents are between ball and goal line
2. : in poor taste : off-color
comedy line cut out as being off side
3. : in such position as to cause a finesse to lose
the queen is off side