Definition of reaction:

part of speech: noun

Reactive, reactionary.

part of speech: noun

Action following and contrary to previous action; mutual action.

part of speech: noun

Return action or influence; response to influence or effort exerted; a return to a former or opposite state of things; contrary action following the effects of other action; the equal force that a body exerts on an opposing force; chemical change; a chemical process or its result.

Usage examples for reaction:

Word of the day


A method of wall painting in water colors on fresh plaster; a picture made on plaster. ...