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

More than 350 million customers used it over the past year, while active users nearly doubled and interactions increased more than fivefold year over year in the second quarter, CEO Andy Jassy said. — Alexa Lomonaco, CNBC, 9 Oct. 2026

Researchers, such as the complexity theorist Stuart Kauffman, began to construct simple mathematical models of the networks of gene interactions. — Quanta Magazine, 9 Oct. 2026

However, these fragile states can deteriorate through interactions with the environment and imperfections in hardware. — Aamir Khollam, Interesting Engineering, 9 Oct. 2026

But conflict-of-interest policies that restrict or manage interactions between companies and doctors probably improved prescribing practices, the analysis found. — Ed Silverman, STAT, 9 Oct. 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