Definition of interaction noun in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

(of two or more people, things etc) to act, or have some effect, on each other.

If you interact with someone — by talking, looking, sharing, or engaging in any kind of action that involves the two of you — you can be said to have had an interaction with that person.

interaction noun [C, U] (THINGS) the way that two or more things combine and have an effect on each other

Apr 3, 2011 · The meaning of INTERACTION is mutual or reciprocal action or influence. How to use interaction in a sentence.

One possible drug interaction can involve the drugs working together to have a stronger effect. An interaction between medications occurs when the effectiveness of one medication is altered by …

in•ter•ac•tion, n. [uncountable] social interaction between men and women. [countable] day-to-day interactions. in•ter•ac•tive, adj.: Interactive video lets the user decide what to see on the screen.

Interaction is a reciprocal action or influence that occurs between two or more objects, substances, people or systems, where each has an effect on the other. It could be in form of communication, …

Established in 1984, InterAction is the leading national alliance of NGOs and partners in the United States. With a focus on serving the world’s impoverished and vulnerable populations, our …

Feb 21, 2026 · interaction (countable and uncountable, plural interactions) The situation or occurrence in which two or more objects or events act upon one another to produce an effect; the effect resulting …