Umpire – the official lined up five yards away from the line of scrimmage on the defensive side; his main duties involve monitoring the linemen for holding, ineligible linemen downfield, etc.

Unbalanced Line – a formation of the offensive line with more linemen on one side of center than the other

Unnecessary Roughness – a 15 yard penalty for a block or tackle that seems needlessly aggressive or puts the player at unnecessary risk for injury

Unsportsmanlike Conduct – a 15 yard penalty for taunting or behaving in another inappropriate manner

Uprights – two vertical bars on the crossbar, a field goal attempt must pass between the two uprights to be successful 

Veer – a running play in which the ball is handed off to the “Back” and his route is determined by the defensive alignment

Vince Lombardi Trophy – the trophy, named after famous head coach Vince Lombardi, awarded to the winner of the Super Bowl

Weak Side – the side of the offensive line without the tight end

Wideout – See “Split End”

Wide Receiver – See “Receiver”

Wild Card – playoff opportunities given to teams that haven’t won their divisions, but have the best records out of the remaining teams

Wing Back – a running back employed in a wing formation

Winning Percentage – a team’s success in a given number of games; calculated by adding wins plus (ties divided by 2) divided by the total number of games played

Wishbone Formation – an offensive formation including a full back lined up behind the quarterback with two half backs lined up on either side of the fullback