interaction

noun

in·​ter·​ac·​tion ˌin-tər-ˈak-shən 

: mutual or reciprocal action or influence

interactional

ˌin-tər-ˈak-sh(ə-)nəl 

adjective

Synonyms of interaction

• relation
• intercourse
• dealings

Examples of interaction in a Sentence

she guessed from the friendly interaction that they were close to the other parents in the organization

Recent Examples on the Web

For those who prefer more direct interaction during the resolution process, the firm’s smaller-company structure may offer a more hands-on experience than larger national providers. —Roxanne Downer, USA Today, 13 Feb. 2026

Zurek’s theory of quantum Darwinism — which, again, uses nothing more than the standard equations of quantum mechanics applied to the interaction of the quantum system and its environment — makes predictions that are now being tested experimentally. —Quanta Magazine, 13 Feb. 2026

Cutting off interaction stops the scam immediately. —Kurt Knutsson, FOXNews.com, 13 Feb. 2026

But behind the scenes, Epstein appeared to still be coordinating at least one other woman’s interactions with Kimbal Musk. —Eva Roytburg, Fortune, 13 Feb. 2026

Word History

First Known Use

1832, in the meaning defined above

Rhymes for interaction

• benefaction
• counteraction
• liquefaction
• putrefaction
• rarefaction
• satisfaction
• stupefaction
• tumefaction
• abstraction
• attraction
• compaction
• contraction

Kids Definition

interaction

noun

in·​ter·​ac·​tion ˌint-ə-ˈrak-shən 

: the action or influence of people, groups, or things on one another

interactional

-shnəl 

-shən-ᵊl

adjective

Medical Definition

interaction

noun

in·​ter·​ac·​tion ˌint-ə-ˈrak-shən 

: mutual or reciprocal action or influence

interaction of the heart and lungs

interactional

-shnəl, -shən-ᵊl 

adjective