invalid
1 Americannoun
-
an infirm or sickly person.
-
a person who is too sick or weak to take care of their own needs.
My father was an invalid the last ten years of his life.
-
Archaic. a member of the armed forces disabled for active service.
adjective
-
unable to care for oneself due to infirmity or disability.
his invalid sister.
-
of or for invalids.
invalid diets.
-
(of things) in poor or weakened condition.
the invalid state of his rocking chair.
verb (used with object)
-
to affect with disease; make an invalid.
He was invalided for life.
-
to remove from or classify as not able to perform active service, as an invalid.
-
British. to remove or evacuate (military personnel) from an active theater of operations because of injury or illness.
verb (used without object)
adjective
-
not valid; not founded in truth, fact, or logic, and hence weak and indefensible; unsound; untenable.
The entire argument depends on an invalid assumption.
- Synonyms:
- incorrect, inaccurate, false, erroneous, unsubstantiated, unfounded, groundless, baseless
-
deficient in effectiveness; inadequate.
Self-perception is an invalid method of judging one's own biases.
-
void or without legal force, as a contract.
Without the grandfather clause, thousands of such warranties would now be invalid. The coupon is invalid in our state.
- Synonyms:
- null and void
-
not accepted or permitted because a required element or the necessary form is lacking; not usable.
Anything with fewer than five characters is an invalid password, and you’ll get an error message prompting you to pick something more secure.
noun
adjective
verb
-
to cause to become an invalid; disable
-
(usually foll by out; often passive) to require (a member of the armed forces) to retire from active service through wounds or illness
adjective
-
not valid; having no cogency or legal force
-
logic (of an argument) having a conclusion that does not follow from the premises: it may be false when the premises are all true; not valid
Usage
It is best to avoid using the term invalid when referring to people with chronic illnesses or disabilities
Other Word Forms
Derived Forms
Inflected Forms
Nouns
Participles
Conjugated Forms
Present
-
invalidsimple
-
invalidssimple
-
have invalidedperfect
-
has invalidedperfect
-
am invalidingprogressive
-
are invalidingprogressive
-
is invalidingprogressive
-
have been invalidingperfect progressive
-
has been invalidingperfect progressive
Past
-
invalidedsimple
-
had invalidedperfect
-
was invalidingprogressive
-
were invalidingprogressive
-
had been invalidingperfect progressive
Future
Etymology
Origin of invalid1
First recorded in 1635–45; from French invalide, from Latin invalidus “weak, feeble, infirm”; See in- 3, valid
Origin of invalid2
First recorded in 1630–40; from Latin invalidus “weak, feeble”; see invalid 1
Explanation
A person who is very sick or injured and needs frequent care is an invalid. Also, something no longer current or useful is invalid. The main uses of this word have to do with people and things that don't work very well anymore. A driver's license that has expired is invalid — it needs to be renewed. If you lost your health insurance, it's invalid. People who are called invalids are disabled or incapacitated severely. Be careful with this word, because some think it is inappropriate, since it sounds as if some people are not as valid as others based on physical capability.
Vocabulary lists containing invalid
"Sorry, Wrong Number," Vocabulary from the play
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
"Sorry, Wrong Number," Vocabulary from the play
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
The Suffix -id, Part 1
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
Even if your grandmother changed her will because she was tired of arguing with your father, that doesn’t automatically make the change legally or morally invalid.
From MarketWatch ● Jul. 6, 2026
Online retailers selling the physical edition have stated that, as with other digital game codes, the one being offered for GTA 6 is single-use and will become invalid after it is redeemed.
From BBC ● Jun. 26, 2026
Shadow fleet vessels frequently change the flags they fly, a practice known as flag-hopping, or use invalid registrations in an attempt to escape tracking.
From Barron's ● Jun. 1, 2026
The basic problem, as these courts identified, is that the government failed to accuse these doctors of any plausibly unlawful conduct, rendering the subpoenas invalid.
From Slate ● May 19, 2026
I didn’t want to lie in bed like an invalid while Luke was out there planning to destroy the Western world.
From "The Lightning Thief" by Rick Riordan
Patient outcomes varied depending on whether you asked the officer who lost fighters, the ferryman who shuttled the sick, the doctor who treated invalids or the adjutant who buried bodies.
From Scientific American ● Jul. 23, 2022
British food manufacturers and brother duo James and William Horlick created malted milk powder as a nutritional supplement marketed for "infants and invalids."
From Salon ● Aug. 21, 2021
Wealthy invalids flocked to the south Devon town for its sunshine and sea air.
From The Guardian ● Feb. 15, 2021
Tuesday's voting was reserved for the aged, invalids, people in hospitals and the military.
From Fox News ● Apr. 26, 2019
If you break your head or back-bone you will be very unfortunate, policemen can direct the traffic so that there won't be too many invalids to go to hospital.
From "The God of Small Things" by Arundhati Roy
Marc Leonard and the wonderful lynchpin at the back, Craig Halkett, were invalided out of the action.
From BBC ● May 9, 2026
Last August, the U.S. military’s top appeals court upheld Bergdahl’s conviction, rejecting arguments that public comments by Trump and McCain should have invalided his prosecution, Military.com reported.
From Fox News ● Feb. 18, 2021
He knows that the old songs give “the invalided and senile a musical opportunity to re-court their wives, re-raise their children and re-fight their wars.”
From New York Times ● Sep. 21, 2017
Just as Connie Willis salutes the resilience of Brits in her fiction about England during World War II, Kowal pays similar tribute in this novel through her depiction of grandmotherly Mrs. Richardson and invalided Lt.
From Seattle Times ● Sep. 4, 2016
One fourth of the sailors of the English navy are sent home invalided every year, and one tenth of them die from the effects of foul air of their cabins.
From Martyria or Andersonville Prison by Hamlin, Augustus C.
There he called on Senator James A. .Reed of Missouri, who is invaliding from a recent illness.
From Time Magazine Archive
In hospital they are always professing to a recovery from fever that their pallid faces and enlarged spleens belie, and they take not kindly to any suggestion of invaliding.
From Sketches of the East Africa Campaign by Dolbey, Robert Valentine
Sent back by me eventually to Korogwe with a letter advising his invaliding out of the country, he opened and read my report upon the way.
From Sketches of the East Africa Campaign by Dolbey, Robert Valentine
Invalided to India 50 As above, includes instances of invaliding more than one as separate items.
From With a Highland Regiment in Mesopotamia 1916—1917 by Anonymous
The next in seniority was entirely adverse to the invaliding, as, without he could invalide too, he would have to go to the West Indies in the place of our surgeon.
From Rattlin the Reefer by Marryat, Frederick
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
