Invalid

//ɪnˈvæl.ɪd// adj, noun, verb

adj, noun, verb ·Common ·High school level

Definitions

Noun

1
Any person with a disability or illness. dated, offensive, sometimes
2
someone who is incapacitated by a chronic illness or injury wordnet
3
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. dated, offensive, sometimes
4
A disabled member of the armed forces; one unfit for active duty due to injury. archaic

Verb

1
To exempt from (often military) duty because of injury or ill health. British, transitive
"He was invalided home after the car crash."
2
injure permanently wordnet
3
To make invalid or affect with disease. transitive
4
force to retire, remove from active duty, as of firemen wordnet

Adjective

1
Not valid; not true, correct, acceptable or appropriate.
"Your argument is invalid because it uses circular reasoning."
2
Suffering from disability or illness. not-comparable
"Invalidism therefore referred to a lack of power as well as a tendency toward illness. It is for this reason that I choose to discuss the invalid woman rather than just the ill one."
3
Intended for use by an invalid. not-comparable

Adjective

1
no longer valid wordnet
2
having no cogency or legal force wordnet

Synonyms

disable fallacious false spurious illegitimate shut in

Antonyms

Example

"The contract, if you were forced to sign it, is invalid."

Etymology

Etymology 1

From in- + valid.

Etymology 2

From Middle French invalide, from Latin invalidus (“infirm, weak”), from in- (“not”) + validus (“strong”).

Related phrases

fabulous invalid invalid carriage invalid chair invalid out invalid stout armed forces invalid carriage

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Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.