The meaning of INVALID is not valid. How to use invalid in a sentence.

INVALID definition: 1. An invalid document, ticket, law, etc. is not legally or officially acceptable: 2. An invalid…. Learn more.

Define invalid. invalid synonyms, invalid pronunciation, invalid translation, English dictionary definition of invalid. n. One who is incapacitated by a chronic illness or disability. adj. 1. Incapacitated by illness …

Sep 22, 2025 · invalid (comparative more invalid, superlative most invalid) Not valid; not true, correct, acceptable or appropriate. Your argument is invalid because it uses circular reasoning. This invalid …

If an action, procedure, or document is invalid, it cannot be accepted, because it breaks the law or some official rule. The trial was stopped and the results declared invalid. We cannot accept liability if you …

INVALID definition: an infirm or sickly person. See examples of invalid used in a sentence.

Definition of invalid adjective in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

a person who is too sick or weak to care for himself or herself: My father was an invalid the last ten years of his life. [Archaic.]a member of the armed forces disabled for active service.

The judge declared that the contract was invalid. Her husband has become an invalid. She cares for her invalid husband at home. He was invalided out of the army. He was invalided home.

To affect with disease; render an invalid: chiefly in the past participle. To register as an invalid; enroll on the list of invalids in the military or naval service; give leave of absence from duty on account of ill …