'Invalid' definitions:

Definition of 'invalid'

(from WordNet)
adjective
Having no cogency or legal force; "invalid reasoning"; "an invalid driver's license" [ant: valid]
adjective
No longer valid; "the license is invalid"
noun
Someone who is incapacitated by a chronic illness or injury [syn: invalid, shut-in]
verb
Force to retire, remove from active duty, as of firemen
verb
Injure permanently; "He was disabled in a car accident" [syn: disable, invalid, incapacitate, handicap]

Definition of 'Invalid'

From: GCIDE
  • Invalid \In*val"id\, a. [Pref. in- not + valid: cf. F. invalide, L. invalidus infirm, weak. Cf. Invalid infirm.] [1913 Webster]
  • 1. Of no force, weight, or cogency; not valid; weak. [1913 Webster]
  • 2. (Law) Having no force, effect, or efficacy; void; null; as, an invalid contract or agreement. [1913 Webster]

Definition of 'Invalid'

From: GCIDE
  • Invalid \In"va*lid\ (?; 277), n. [F. invalide, n. & a., L. invalidus, a. See Invalid null.] A person who is weak and infirm; one who is disabled for active service; especially, one in chronic ill health who is unable to care for himself. [1913 Webster]

Definition of 'Invalid'

From: GCIDE
  • Invalid \In"va*lid\, a. [See Invalid, n.] Not well; feeble; infirm; sickly; as, he had an invalid daughter. [1913 Webster]

Definition of 'Invalid'

From: GCIDE
  • Invalid \In"va*lid\, v. t.
  • 1. To make or render invalid or infirm. "Invalided, bent, and almost blind." --Dickens. [1913 Webster]
  • 2. To classify or enroll as an invalid. [1913 Webster]
  • Peace coming, he was invalided on half pay. --Carlyle. [1913 Webster]

Synonyms of 'invalid'

From: Moby Thesaurus