backfield

noun Football.

1. (used with a plural verb) the members of the team who, on offense, are stationed behind the linemen and, on defense, behind the linebackers.
2. their positions considered as a unit.
3. the area where the backs play.

noun American football

1. the backfield (sometimes functioning as plural) the quarterback and running backs in a team
2. the area behind the line of scrimmage from which the backfield begin each play