I. ri-ˈsi-prə-kəl adjective
Etymology: Latin reciprocus returning the same way, alternating
Date: 1570
1.
a. : inversely related : opposite
b. : 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
2. : shared, felt, or shown by both sides
3. : serving to reciprocate : consisting of or functioning as a return in kind
the reciprocal devastation of nuclear war
4.
a. : mutually corresponding
agreed to extend reciprocal privileges to each other's citizens
b. : marked by or based on reciprocity
reciprocal trade agreements
• re·cip·ro·cal·ly -k(ə-)lē adverb
II. noun
Date: 1570
1. : something in a reciprocal relationship to another
2. : either of a pair of numbers (as 2/3 and 3/2 or 9 and 1/9) whose product is one ; broadly : multiplicative inverse