https://www.vocabulary.com/lists/378811
https://quizlet.com/110545538/american-football-vocabulary-flash-cards/
Down: A period of action that starts when the ball is put into play and ends when the ball is ruled dead (meaning the play is completed). The offense gets four downs to advance the ball 10 yards. If it fails to do so, it must surrender the ball to the opponent, usually by punting on the fourth down.
End zone: A 10-yard-long area at each end of the field. You score a touchdown when you enter the end zone in control of the football. If you’re tackled in your own end zone while in possession of the football, the other team gets a safety.
Fumble: The act of losing possession of the ball while running with it or being tackled. Members of the offense and defense can recover a fumble. If the defense recovers the fumble, the fumble is called a turnover.
Handoff: The act of giving the ball to another player. Handoffs usually occur between the quarterback and a running back.
Huddle: When the 11 players on the field come together to discuss strategy between plays. On offense, the quarterback relays the plays in the huddle.
Incompletion: A forward pass that falls to the ground because no receiver could catch it, or a pass that a receiver dropped or caught out of bounds.
Interception: A pass that’s caught by a defensive player, ending the offense’s possession of the ball.
Kickoff: A free kick (meaning the receiving team can’t make an attempt to block it) that puts the ball into play. A kickoff is used at the start of the first and third quarters and after every touchdown and successful field goal.
Line of scrimmage: An imaginary line that extends from where the football is placed at the end of a play to both sides of the field. Neither the offense nor the defense can cross the line until the football is put in play again.
Punt: A kick made when a player drops the ball and kicks it while it falls toward his foot. A punt is usually made on a fourth down when the offense must surrender possession of the ball to the defense because it couldn’t advance 10 yards.
Snap: The action in which the ball is hiked (tossed between the legs) by the center to the quarterback, to the holder on a kick attempt, or to the punter. When the snap occurs, the ball is officially in play and action begins.
Touchdown: A score, worth six points, that occurs when a player in possession of the ball crosses the plane of the opponent’s goal line, when a player catches the ball while in the opponent’s end zone, or when a defensive player recovers a loose ball in the opponent’s end zone.
Offside - When any part of a player’s body is beyond the line of scrimmage or free kick line when the ball is put into play.
Holding (Offensive) - When an offensive player uses his hands, arms, or other parts of his body to prevent a defensive player from tackling the ball carrier.
Holding (Defensive) - When a defensive player tackles or holds an offensive player other than the ball carrier.
False Start - When an interior lineman on the offensive team moves prior to the snap of the ball, or when any offensive player makes a quick, abrupt movement prior to the snap of the ball.
Pass Interference - A judgment call made by an official who sees a defensive player make contact with the intended receiver before the ball arrives, thus restricting his opportunity to catch the forward pass.
Roughing the Passer - When a defensive player makes direct contact with the quarterback after the quarterback has released the ball.
Personal Foul - An illegal, flagrant foul considered risky to the health of another player.
Field dimensions: The dimensions of a football field haven’t changed much through the years. The field has been 100 yards long and 53 1/3 yards wide since 1881. In 1912, the two end zones were established at 10 yards deep and have remained so ever since. Consequently, all football games are played on a rectangular field that’s 360 feet long x 160 feet wide.
The marks on the field: All over the field, you see a bunch of white lines. Every line has a special meaning:
End lines: The lines at each end of the field.
Sidelines: The lines along each side of the field.
Goal lines: The goal lines are 10 yards inside and parallel to each end line.
Field of play: The area bounded by the goal lines and sidelines.
50-yard line: The field is divided in half by the 50-yard line, which is located in the middle of the field.
End zones: The two areas bounded by the goal lines, end lines, and sidelines.
Yard lines: Run parallel to the goal lines at intervals of 5 yards and are marked across the field from sideline to sideline. These lines stop 8 inches short of the 6-foot solid border in the NFL.
The above is from - http://www.dummies.com/sports/football/football-for-dummies-usa-edition-cheat-sheet/