The meaning of REACTION is the act or process or an instance of reacting. How to use reaction in a sentence.

REACTION definition: a reverse movement or tendency; an action in a reverse direction or manner. See examples of reaction used in a sentence.

A chemical reaction is the change that happens when two or more substances are mixed with each other.

A reaction is an action taken in response to something. If you're telling your parents that you want to move out, you'll see by their reaction that they're sad about it.

Usage: Reaction is used to refer both to an instant response (her reaction was one of amazement) and to a considered response in the form of a statement (the Minister gave his reaction to the court's …

Reaction is used to refer both to an instant response (her reaction was one of amazement) and to a considered response in the form of a statement (the Minister gave his reaction to the court's decision).

reaction meaning, definition, what is reaction: something that you feel or do because of...: Learn more.

Dec 28, 2025 · reaction (plural reactions) An action or statement in response to a stimulus or other event.

Reaction Look up reaction in Wiktionary, the free dictionary. Reaction may refer to a process or to a response to an action, event, or exposure.

reaction noun (CHANGE) a change in the way people behave or think because they do not agree with the way people behaved or thought in the past: