What is a rush in the NFL?

Answer 1

Rushing in U.S. football is the act of the ofense running with the ball from the line of scrimmage. As opposed to throwing it forward (passing)or running it back from a punt or kickoff.

Answer 2

Rushing the football means that after the Quarter-Back takes the snap he turns around and either tosses or hands the ball to his Running-Back who runs the ball as best as he can.

Answer 3

When a player is handed the ball and runs to gain yards instead of passing it.

Or it is when the QB is about to get sacked by defensive players and tries to get away.