something (a term or expression or concept) that has a reciprocal relation to something else; "risk is the reciprocal of safety"
of or relating to the multiplicative inverse of a quantity or function; "the reciprocal ratio of a:b is b:a"
concerning each of two or more persons or things; especially given or done in return; "reciprocal aid"; "reciprocal trade"; "mutual respect"; "reciprocal privileges at other clubs"