noun, plural af·fin·i·ties.


of or relating to persons who share the same interests: to arrange charter flights for opera lovers and other affinity groups.

Nearby words

  1. affine geometry,
  2. affine group,
  3. affined,
  4. affinely,
  5. affinitive,
  6. affinity card,
  7. affinity group,
  8. affirm,
  9. affirmance,
  10. affirmant

Origin of affinity

1275–1325; Middle English affinite < Middle French < Latin affīnitās connection by marriage. See affine, -ity

Related formsnon·af·fin·i·ty, noun, plural non·af·fin·i·ties, adjective

Can be confusedaffinity infinity Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for affinity

British Dictionary definitions for affinity


noun plural -ties

(foll by with or for) a natural liking, taste, or inclination towards a person or thing
the person or thing so liked
a close similarity in appearance or quality; inherent likeness
relationship by marriage or by ties other than of blood, as by adoptionCompare consanguinity
similarity in structure, form, etc, between different animals, plants, or languages
  1. the tendency for two substances to combine; chemical attraction
  2. a measure of the tendency of a chemical reaction to take place expressed in terms of the free energy changeSymbol: A
biology a measure of the degree of interaction between two molecules, such as an antigen and antibody or a hormone and its receptor
Derived Formsaffinitive, adjective

Word Origin for affinity

C14: via Old French from Latin affīnitāt- connected by marriage, from affīnis bordering on, related

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 affinity



c.1300, "relation by marriage" (as opposed to consanguinity), from Old French afinité (12c.), from Latin affinitatem (nominative affinitas) "neighborhood, relationship by marriage," noun of state from affinis "adjacent," also "kin by marriage," literally "bordering on," from ad- "to" (see ad-) + finis "a border, an end" (see finish). Used figuratively since c.1600 of structural relationships in chemistry, philology, etc. Meaning "natural attraction" (as though by family) is from 1610s.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for affinity




An attraction or force between particles that causes them to combine.
The attraction between an antigen and an antibody.
A relationship or resemblance in structure between species that suggests a common origin.
The selective staining of a tissue by a dye.
The selective uptake of a dye, chemical, or other substance by a tissue.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for affinity



A relationship or resemblance in structure between species that suggests a common origin.
An attraction or force between particles that causes them to combine, as the attraction between an antigen and an antibody.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.