To make invalid. Especially applied to contract law. / To make or declare (an argument, statement, or theory) unsound or erroneous; disprove.

Third-person singular simple present indicative form of invalidate

Made invalid.

simple past tense and past participle of invalidate

plural of invalid

present participle of invalidate

The act of invalidating, or the state of being invalidated

Not valid; not true, correct, acceptable or appropriate.

(Britain, transitive) To exempt from (often military) duty because of injury or ill health. / (transitive) To make invalid or affect with disease.

(dated, sometimes offensive) Any person with a disability or illness.