From in- + valid.

• enPR: ĭn-vă'lĭd, IPA: /ɪnˈvæl.ɪd/

invalid

1. Not valid; not true, correct, acceptable or appropriate.

   Your argument is invalid because it uses circular reasoning.

   This invalid contract cannot be legally enforced.

• nonvalid
• disallowed

• valid

• French: invalide
• German: ungültig
• Italian: irrito, invalido
• Portuguese: inválido
• Russian: недействи́тельный
• Spanish: inválido

From , from , from in- ("not") + validus ("strong").

• enPR: ĭn'və-lĭd, IPA: /ˈɪn.və.lɪd/

invalid (plural invalids)

1. (dated, sometimes, offensive) Any person with a disability or illness.
2. (dated, sometimes, offensive) A person who is confined to home or bed because of illness, disability or injury; one who is too sick or weak to care for themselves.
3. (archaic) A disabled member of the armed forces; one unfit for active duty due to injury.

• French: invalide
• German: Invalide, Invalidin
• Italian: invalido, invalida
• Portuguese: inválido, inválida
• Russian: инвали́д
• Spanish: inválido, inválida

• French: invalide
• German: Bettlägriger, Schwerkranker
• Portuguese: inválido
• Russian: инвали́д
• Spanish: inválido

invalid (not comparable)

1. Suffering from disability or illness.
2. Intended for use by an invalid.

invalid (invalids, present participle invaliding; simple past and past participle invalided)

1. (British, transitive) To exempt from (often military) duty because of injury or ill health.

   He was invalided home after the car crash.

   • 1989, Richard Curtis, Ben Elton, “Goodbyeee”, in Blackadder Goes Forth:

     Blackadder: Right, Baldrick, this is an old trick I picked up in the Sudan. We tell HQ that I’ve gone insane, and I’ll be invalided back to Blighty before you can say "wibble" — a poor, gormless idiot.

2. (transitive) To make invalid or affect with disease.