Click anywhere to start. This is a simple tool to measure your reaction time. The average (median) reaction time is 273 milliseconds, according to the data collected so far. In addition to measuring …

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

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.

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

Jan 20, 2026 · Noun reaction (plural reactions) An action or statement in response to a stimulus or other event.

reaction, n. meanings, etymology, pronunciation and more in the Oxford English Dictionary

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

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

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.