Nouns

(n)rearwarddirection toward the rear“his outfit marched to the rearward of the tank divisions”

Adjectives

(s)rear, rearwardlocated in or toward the back or rear“the chair's rear legs”, “the rear door of the plane”, “on the rearward side”
(s)rearward, reversedirected or moving toward the rear“a rearward glance”, “a rearward movement”

Adverbs

(r)back, backward, backwards, rearward, rearwardsat or to or toward the back or rear“he moved back”, “tripped when he stepped backward”, “she looked rearward out the window of the car”