react in Finnish

(transitive, now, rare) To act or perform a second time; to do over again; to reenact. [from 17th c.]

(physics, intransitive) To return an impulse or impression; to resist the action of another body by an opposite force

(physics, intransitive) To return an impulse or impression; to resist the action of another body by an opposite force

(chemistry, intransitive) To act upon each other; to exercise a reciprocal or a reverse effect, as two or more chemical agents; to act in opposition.