n (American football) the five players (the center, the two offensive guards and the two offensive tackles) lined up on the middle of the offensive side within a yard of the line of scrimmage
n (American football) the seven legally obligatory players lined up on the offensive side within a yard of the line of scrimmage
n (American football) all the offensive players, whether obligatory or not, lined up one yard or less from the offensive line of scrimmage