invalid
1 Americannoun
-
invalids
plural
-
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)
-
invalids,
present (3rd person singular)
-
invalided,
past participle, past
-
invaliding
present participle
-
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)
-
invalids,
present (3rd person singular)
-
invalided,
past participle, past
-
invaliding
present participle
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
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"Sorry, Wrong Number," Vocabulary from the play
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The Suffix -id, Part 1
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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:
The deputy federal public defenders said a defense analysis identified invalid service as acting or de facto U.S. attorneys in at least 16 districts across the country.
From Los Angeles Times ● Sep. 5, 2026
Mateta also faces an uncertain future after BBC Sport's revelation on Saturday that the France striker has been arguing the final year on his Palace contract should be ruled invalid.
From BBC ● Aug. 26, 2026
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
Bellows, now Maine’s secretary of state and a gubernatorial candidate, recently struck the question from the ballot due to invalid signatures, a decision that’s now in court.
From Slate ● Jun. 16, 2026
She still felt bad about asking Maya whether or not the adoption would be invalid.
From "Far from the Tree" by Robin Benway
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
By this time, Vincent and McNeish were complete invalids and stayed in the cave in a stupor.
From "Shipwreck at the Bottom of the World" by Jennifer Armstrong
Getting invalided out of the 2017 Lions tour caused him untold angst.
From BBC ● Mar. 27, 2023
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
He could have stayed on in hospital and would very likely have been invalided back to England eventually.
From Caught by the Turks by Francis Yeats-Brown
There he called on Senator James A. .Reed of Missouri, who is invaliding from a recent illness.
From Time Magazine Archive
That evening Dr Thompson made the captain’s punch, having carefully locked up in his largest tea-chest his invaliding suit.
From Rattlin the Reefer by Frederick Marryat
The aspirant for invaliding sat himself down again at one end of the table, as the captains did at the other.
From Rattlin the Reefer by Frederick Marryat
In the interim, don’t forget the old clothes—the invaliding suit.
From Rattlin the Reefer by Frederick Marryat
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
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.
