affinity

American  

[uh-fin-i-tee] / əˈfɪn ɪ ti /

noun

affinities plural

1. a natural liking for or attraction to a person, thing, idea, etc.

   Synonyms:

   bent, leaning, sympathy, fondness, partiality

   Antonyms:

   aversion, dislike

2. a person, thing, idea, etc., for which such a natural liking or attraction is felt.

3. relationship by marriage or by ties other than those of blood (distinguished from consanguinity).

4. inherent likeness or agreement; close resemblance or connection.

   Synonyms:

   compatible, similarity

   Antonyms:

   disparity, dissimilarity

5. Biology. the phylogenetic relationship between two organisms or groups of organisms resulting in a resemblance in general plan or structure, or in the essential structural parts.

6. Chemistry. the force by which atoms are held together in chemical compounds.

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adjective

1. of or relating to persons who share the same interests.

   to arrange charter flights for opera lovers and other affinity groups.

affinity British  

/ əˈfɪnɪtɪ /

noun

1. a natural liking, taste, or inclination towards a person or thing

2. the person or thing so liked

3. a close similarity in appearance or quality; inherent likeness

4. relationship by marriage or by ties other than of blood, as by adoption Compare consanguinity

5. similarity in structure, form, etc, between different animals, plants, or languages

6. chem

   1. the tendency for two substances to combine; chemical attraction

   2.  A.  a measure of the tendency of a chemical reaction to take place expressed in terms of the free energy change

7. biology a measure of the degree of interaction between two molecules, such as an antigen and antibody or a hormone and its receptor

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affinity Scientific  

/ ə-fĭn′ĭ-tē /

1. A relationship or resemblance in structure between species that suggests a common origin.

2. An attraction or force between particles that causes them to combine, as the attraction between an antigen and an antibody.

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Other Word Forms

• affinitive
  adjective
• nonaffinity
  noun

Etymology

Origin of affinity

First recorded in 1275–1325; Middle English affinite, from Middle French, from Latin affīnitās “connection by marriage”; equivalent to affine + -ity

Explanation

If you get along with someone very well, you have an affinity with them. Sometimes opposites attract, so you might feel a strange affinity to someone who is seemingly very different from you. When you are attracted to someone or something a great deal, we say that you have an affinity, a natural connection. Likewise, scientists use affinity to describe organisms that are alike or resemble each other. Interestingly, the Middle English word, affinite, originally applied to people who were connected or related by marriage, rather than by biology.

Example Sentences

Their results suggested that Novel VK had stronger binding affinity for mGluR1 than MK-4.

From Science Daily • May 27, 2026

There have been other touch points, like the affinity some Task Force officers have for the Punisher logo, that crosses from the fictional into reality.

From Los Angeles Times • May 6, 2026

OpenAI said in its blog post it added the instruction to curb Codex and its underlying model's "strange affinity for goblins".

From BBC • Apr. 30, 2026

“With Ryan’s huge success with Wrexham, he has a great affinity for the U.K.,” the insider told the outlet, noting that the actress “could rebrand there.”

From MarketWatch • Apr. 30, 2026

The old man’s backwoods savvy, his affinity for the wilderness, left a deep impression on the boy.

From "Into the Wild" by Jon Krakauer

Related Words

• affection
• closeness
• fondness
• leaning
• rapport
• sympathy
• weakness