also off-side, offsides, "on the wrong side;" from off (prep.) + side (n.). From 1867 in various sporting senses, originally in English football, between the ball and the opponent's goal during play.
the touchdown was nullified because the left tackle was offside
off-season
offset
offshoot
off-shore
offshoring
offside
off-site
offspring
off-stage
off-street
off-target
