say it: ri-SI-pruh-kuhl
reciprocal is a noun and adjective meaning "something (a term or expression or concept) that has an inverse relation to something else". It carries 5 recorded senses.
something (a term or expression or concept) that has an inverse relation to something else
“risk is the reciprocal of safety”
(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
mathematics
hybridization involving a pair of crosses that reverse the sexes associated with each genotype
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”
of or relating to the multiplicative inverse of a quantity or function
“the reciprocal ratio of a:b is b:a”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for reciprocal come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.