[ in-ter-ak-shuh n ]
/ ˌɪn tərˈæk ʃən /


reciprocal action, effect, or influence.
  1. the direct effect that one kind of particle has on another, in particular, in inducing the emission or absorption of one particle by another.
  2. the mathematical expression that specifies the nature and strength of this effect.

Origin of interaction

First recorded in 1825–35; inter- + action

OTHER WORDS FROM interaction

in·ter·ac·tion·al, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for interactional

/ (ˌɪntərˈækʃən) /


a mutual or reciprocal action or influence
physics the transfer of energy between elementary particles, between a particle and a field, or between fieldsSee strong interaction, electromagnetic interaction, fundamental interaction, gravitational interaction, weak interaction, electroweak interaction

Derived forms of interaction

interactional, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012