(intransitive) To act in response. / (transitive, now rare) To act or perform a second time; to do over again; to reenact.

(Internet) An emoji used to express a reaction to a post on social media.

simple past tense and past participle of react

present participle of react

Third-person singular simple present indicative form of react

plural of react

Wood that forms (in a woody plant) in response to gravity, which differs from normal wood in ways that give it additional strength so that a branch (etc) can resist bending downward or breaking.

plural of Mannich reaction

plural of reactability

A process of alternating vasoconstriction and vasodilation in extremities exposed to cold.