- reciprocate (v.)
[reciprocate 词源字典]
- "to return, requite," 1610s, back-formation from reciprocation, or else from Latin reciprocatus, past participle of reciprocare "rise and fall, move back and forth; reverse the motion of," from reciprocus (see reciprocal). Related: Reciprocated; reciprocating.[reciprocate etymology, reciprocate origin, 英语词源]