English Reference
noun

interaction

n.
US /ˌɪnɝˈækʃən/ UK /ˌɪntəɹˈækʃən/ in·ter·ac·tion UK spelling interaction's, interaction's

  1. 01 B2 Upper Intermediate

    a conversation or an occasion where people communicate or spend time together.

    the process by which people act and react in relation to others through communication or shared activity.

    Simple

    The teacher encouraged more interaction between the students during the group project.

    In context

    The workshop was designed to facilitate meaningful interaction between department heads who rarely had the opportunity to collaborate in person.

    Usage

    Often used with the preposition 'between' or 'with'.

  2. 02 B2 Upper Intermediate AcademicTechnical Science

    the way that two or more things have an effect on each other when they are put together.

    the reciprocal action or influence of two or more objects, substances, or forces upon each other.

    Simple

    Scientists are studying the interaction between the two chemicals to see if they are dangerous.

    In context

    The complex interaction between rising sea temperatures and atmospheric pressure systems has led to increasingly unpredictable weather patterns in the region.

    Usage

    Commonly used in scientific and academic contexts to describe cause-and-effect relationships.

    interplayinterrelation

Usage complex interaction · direct interaction · dynamic interaction

Anyone trying out a new medication should run it by their care provider to make sure there is no potential negative interaction with any other medications they use.

The Guardian· 14 Aug 2026

The company expects AI to handle routine interactions while human agents move into more complex roles.

BBC News· 4 Aug 2026

Borrowed from Medieval Latin interāctiō.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin la-med interāctiō
Level B2 · Upper Intermediate
Frequency Common
Updated