\Re*cip"ro*cate\, v. i. [imp. & p. p.
{Reciprocated}; p. pr. & vb. n. {Reciprocating}.] [L.
reciprocatus, p. p. of reciprocare. See {Reciprocal}.]
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.             --Dryden.
{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.

\Re*cip"ro*cate\, v. t.
To give and return mutually; to make return for; to give in
return; to unterchange; to alternate; as, to reciprocate
favors. --Cowper.