[ri-sip-ruh-kuh l]
See more synonyms for reciprocal on
  1. given or felt by each toward the other; mutual: reciprocal respect.
  2. given, performed, felt, etc., in return: reciprocal aid.
  3. corresponding; matching; complementary; equivalent: reciprocal privileges at other health clubs.
  4. Grammar. (of a pronoun or verb) expressing mutual relationship or action: “Each other” and “one another” are reciprocal pronouns.
  5. inversely related or proportional; opposite.
  6. Mathematics. noting expressions, relations, etc., involving reciprocals: a reciprocal function.
  7. Navigation. bearing in a direction 180° to a given direction; back.
  1. something that is reciprocal to something else; equivalent; counterpart; complement.
  2. Also called multiplicative inverse. Mathematics. the ratio of unity to a given quantity or expression; that by which the given quantity or expression is multiplied to produce unity: The reciprocal of x is 1/x.

Origin of reciprocal

1560–70; < Latin reciproc(us) returning, reciprocal + -al1
Related formsre·cip·ro·cal·i·ty, re·cip·ro·cal·ness, nounre·cip·ro·cal·ly, adverbnon·re·cip·ro·cal, adjective, nounnon·re·cip·ro·cal·ly, adverbun·re·cip·ro·cal, adjectiveun·re·cip·ro·cal·ly, adverb
Can be confusedmutual reciprocal (see synonym study at mutual)common mutual reciprocal (see usage note at mutual)

Synonym study

1. See mutual. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for reciprocal

Contemporary Examples of reciprocal

Historical Examples of reciprocal

British Dictionary definitions for reciprocal


  1. of, relating to, or designating something given by each of two people, countries, etc, to the other; mutualreciprocal friendship; reciprocal trade
  2. given or done in returna reciprocal favour
  3. (of a pronoun) indicating that action is given and received by each subject; for example, each other in the sentence they started to shout at each other
  4. maths of or relating to a number or quantity divided into one
  5. nautical denoting a course or bearing that is 180° from the previous or assumed one
  1. something that is reciprocal
  2. Also called: inverse maths a number or quantity that when multiplied by a given number or quantity gives a product of onethe reciprocal of 2 is 0.5
Derived Formsreciprocality, nounreciprocally, adverb

Word Origin for reciprocal

C16: from Latin reciprocus alternating
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for reciprocal

1560s, with -al (1) + stem of Latin reciprocus "returning the same way, alternating," from pre-Latin *reco-proco-, from *recus (from re- "back;" see re-, + -cus, adjective formation) + *procus (from pro- "forward;" see pro-, + -cus. Related: Reciprocally. The noun meaning "that which is reciprocal" (to another) is from 1560s.

Online Etymology Dictionary, © 2010 Douglas Harper

reciprocal in Medicine


  1. Of or relating to a neuromuscular phenomenon in which the excitation of one group of muscles is accompanied by the inhibition of another.
  2. Of or being a pair of crosses in which the male parent in one cross is of the same genotype or phenotype as the female parent in the other cross.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

reciprocal in Science


  1. Either of a pair of numbers whose product is 1. For example, the number 3 is the reciprocal of 13.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

reciprocal in Culture


The number by which a given number must be multiplied to get a result of one. The reciprocal of one-half, for example, is two.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.