RECIPROCAL

I. adjective Etymology: Latin reciprocus returning the same way, alternating Date: 1570 1. inversely related ; opposite , of, constituting, or resulting from paired crosses in which the kind that supplies the male parent of the first cross supplies the female parent of the second cross and vice versa, shared, felt, or shown by both sides, serving to reciprocate ; consisting of or functioning as a return in kind , 4. mutually corresponding , marked by or based on reciprocity , ~ly adverb II. noun Date: 1570 something in a ~ relationship to another, either of a pair of numbers (as 2/3 and 3/2 or 9 and 1/9) whose product is one