1.VerbOf a quarterback or other player in the backfield, to take a number of steps back from the line of scrimmage immediately after the snap or hike of the ball, to avoid defenders.
"The Tiger quarterback is dropping back to pass."
2.VerbTo move to a lower (or slower) position in a race or competition; to slow down so as to meet up with someone behind oneself
3.VerbUsed other than figuratively or idiomatically: see drop, back.
4.NounThe act by a player in the backfield of dropping back from the line of scrimmage after the hike of the ball.
"With his ankle injury his drop back is not pretty."