reverse

Entry Definition
turning to face in opposite direction, reversing direction, flipping over; (done) in the opposite of the usual way; transforming
(water, tide) its flow reverses, it flows in opposite direction (from the way it was flowing)
(water) it flows back or backward (e.g., reversing falls, backwash on beach)
s/he leaves backing up (e.g., in car)
s/he sees it backward, sees it reversed
s/he, it goes backward, backs up