Synonyms for Backrest:

n.

chair, armrest, armchair, arm, chaise longue, chaise, chesterfield, chaise lounge. artifact (noun)
back.
backrest (noun)
back.

Other synonyms:

chaise, armchair, chaise lounge, chesterfield, armrest, chaise longue. chair. arm. Other relevant words:
armrest, chesterfield, chaise, armchair.