1.something (a term or expression or concept) that has a reciprocal relation to something else;
risk is the reciprocal of safety
2.(mathematics) one of a pair of numbers whose product is 1: the reciprocal of 2/3 is 3/2; the multiplicative inverse of 7 is 1/7
3.hybridization involving a pair of crosses that reverse the sexes associated with each genotype
4.concerning each of two or more persons or things; especially given or done in return;
reciprocal aid
5.of or relating to or suggestive of complementation;
interchangeable electric outlets
6.of or relating to the multiplicative inverse of a quantity or function;
the reciprocal ratio of a:b is b:a