Reciprocate v. i. (past & past part. reciprocated; pres. part. reciprocating) To move forward and backward alternately; to recur in vicissitude; to act interchangeably; to alternate. "One brawny smith the puffing bellows plies, And draws and blows reciprocating air." Reciprocating engine, a steam, air, or gas engine, etc., in which the piston moves back and forth; in distinction from a rotary engine, in which the piston travels continuously in one direction in a circular path.
Reciprocating motion (Mech.), motion alternately backward and forward, or up and down, as of a piston rod.