Толковый словарь английского языка Oxford English Reference - reciprocate

v. 1 tr. return or requite (affection etc.). 2 intr. (foll. by with) offer or give something in return (reciprocated with an invitation to lunch). 3 tr. give and receive mutually; interchange. 4 a intr. (of a part of a machine) move backwards and forwards. b tr. cause to do this. Phrases and idioms reciprocating engine an engine using a piston or pistons moving up and down in cylinders. Derivatives reciprocation n. reciprocator n. Etymology: L reciprocare reciprocat- (as RECIPROCAL)