Definition: Of no force, weight, or cogency; not valid; weak.
Definition: Having no force, effect, or efficacy; void; null; as, an
invalid contract or agreement.
Definition: A person who is weak and infirm; one who is disabled for
active service; especially, one in chronic ill health.
Definition: Not well; feeble; infirm; sickly; as, he had an invalid
daughter.
Definition: To make or render invalid or infirm.
Definition: To classify or enroll as an invalid.