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 power of connection Social interaction is crucial for human development from birth — and remains essential throughout life. —Holly Haber, Dallas Morning News, 20 Mar. 2026

Precision at nanoscale At the core of the system is the interaction between thiol molecules and sulfur vacancies in MoS2. —Neetika Walter, Interesting Engineering, 20 Mar. 2026

Studies show that shark-human interactions are rare, even in high-proximity areas like Southern California, where sharks and people share the water 97% of the time. —CBS News, 20 Mar. 2026

Just recently, Bezos and Sánchez walked the red carpet at the Vanity Fair Oscars after party, and a small interaction between the two captured the internet’s attention. —Lizzie Lanuza, StyleCaster, 20 Mar. 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