Third-person singular simple present indicative form of invalidate

Made invalid.

simple past tense and past participle of invalidate

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

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.