from The American Heritage® Dictionary of the English Language, 4th Edition
- n. One who is incapacitated by a chronic illness or disability.
- adj. Incapacitated by illness or injury.
- adj. Of, relating to, or intended for invalids.
- transitive v. To incapacitate physically.
- transitive v. Chiefly British To release or exempt from duty because of ill health: "I was not quite sick enough to be invalided out, even though I was of no more use” ( Mary Lee Settle).
- adj. Not legally or factually valid; null: an invalid license.
- adj. Falsely based or reasoned; faulty: an invalid argument.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Not valid; not true, correct, acceptable or appropriate.
- n. One who is confined to home or bed because of illness, disability or injury
- n. Any person with a disability.
- adj. Intended for use by an invalid.
- v. To exempt from duty because of injury or ill health.
from the GNU version of the Collaborative International Dictionary of English
- adj. Of no force, weight, or cogency; not valid; weak.
- adj. Having no force, effect, or efficacy; void; null.
- n. 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.
- adj. Not well; feeble; infirm; sickly.
- transitive v. To make or render invalid or infirm.
- transitive v. To classify or enroll as an invalid.
from The Century Dictionary and Cyclopedia
- Not valid; of no force, weight, or cogency; weak.
- In law, having no validity or binding force; wanting efficacy; null; void: as, an invalid contract or agreement.
- Deficient in health; infirm; weak; sick.
- n. An infirm or sickly person; one who is affected by disease or disabled by any infirmity.
- n. Hence Something that is damaged, or the worse for wear, but not so much as to be wholly unserviceable.
- 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 health.
- To cause one's self to be registered as an invalid.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. no longer valid
- adj. having no cogency or legal force
- v. force to retire, remove from active duty, as of firemen
- v. injure permanently
- n. someone who is incapacitated by a chronic illness or injury
From invalid2 (influenced by French invalide, sickly, infirm).
Latin invalidus, weak : in-, not; see in-1 + validus, strong (from valēre, to be strong; see wal- in Indo-European roots).(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin invalidus ("infirm, weak"), from in- ("not") + validus ("strong") (Wiktionary)