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

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.

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.

Your reaction to something that has happened or something that you have experienced is what you feel, say, or do because of 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 …

Dec 14, 2025 · reaction (plural reactions) An action or statement in response to a stimulus or other event.

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 definition: A reverse or opposing action.

Dec 1, 2025 · Reaction rates are reported as either the average rate over a period of time or as the instantaneous rate at a single time. Reaction rates can be determined over particular time intervals …