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

The interactions between the two groups were lovely, as KiiiKiii bowed to their seniors and expressed their admiration to the XG members. — Laura Sirikul, Forbes.com, 19 Aug. 2026

Each person’s character is in some way inspired by the men around them – a million little interactions and observations added up to a complete persona. — Sheena McKenzie, CNN Money, 19 Aug. 2026

Designed for a two-year mission, Swift has been slowly falling to lower and lower altitudes over the past two decades because of interactions with traces of the extreme upper atmosphere that extend out into the realm of low-Earth orbit. — CBS News, 19 Aug. 2026

From infancy onward interactions between intestinal microbes and immune cells help the body distinguish harmless microorganisms from disease-causing pathogens and regulate inflammatory responses. — Encyclopedia Britannica, 19 Aug. 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