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.
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.
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.
to become an invalid.
Other definitions for invalid (2 of 2)
not valid; not founded in truth, fact, or logic, and hence weak and indefensible; unsound; untenable:The entire argument depends on an invalid assumption.
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.
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.
- in·val·id·ly, adverb
- in·val·id·ness, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use invalid in a sentence
A chunk of stimulus payments is missing in action, thanks to a mix up that put as many as 13 million checks into invalid bank accounts.Millions won't get stimulus money before the IRS cut-off date | Courtenay Brown | January 15, 2021 | Axios
Case in point, a recent study from BDEX found that a full 25 percent of device identifiers are invalid.
“Nonetheless, it persisted with these invalid fixes that West Virginia and the Corps have tried and it can’t come to this court now and ask this court to consider that in the equitable balance,” Teaney said.Federal Regulators Are Rewriting Environmental Rules So a Massive Pipeline Can Be Built | by Ken Ward Jr. | December 8, 2020 | ProPublica
In her confirmation hearings in October, too, Barrett seemed to suggest that the individual mandate — if unconstitutional — wouldn’t necessarily mean the rest of the ACA would be invalid.What Happens If the Supreme Court Overturns Obamacare? | Amelia Thomson-DeVeaux (Amelia.Thomson-DeVeaux@abc.com) | November 10, 2020 | FiveThirtyEight
Voters reportedly have raised concerns over rumors that the county lent voters Sharpie pens to cast their votes, allegedly making them invalid, according to the Arizona Republic.Americans assemble in protests and rallies across the country as votes are counted | Danielle Abril | November 5, 2020 | Fortune
The Xinhua News Agency and pro-Beijing groups in Hong Kong say that PopVote is illegal and invalid.Massive Hong Kong Protest Calls for More Democracy | Brendon Hong | July 1, 2014 | THE DAILY BEAST
If the marriage was invalid, Grayson does not have to pay out a dime in alimony as opposed to a divorce.
But again, this is just another way to dismiss her point as invalid and irrelevant.Female Journalist Gets Rape Threats Over Comic Book Criticism | Tauriq Moosa | April 21, 2014 | THE DAILY BEAST
Step 4: Draft a bill to remove every statute signed by Obama because they are all invalid.
Yet his deeds had a way of defying his purposes, and he left the White House as an invalid and perceived as a failure.A Noble Failure: Woodrow Wilson’s Presidency Considered | Michael Kazin | September 8, 2013 | THE DAILY BEAST
The landlady had related the tragic history of the dead mother and the invalid aunt.The Joyous Adventures of Aristide Pujol | William J. Locke
The officer, with less delicacy of attention to the supposed slumbers of an invalid, followed him.The Pastor's Fire-side Vol. 3 of 4 | Jane Porter
Nowadays, however, the latter was somewhat of an invalid, and seldom left their London house in Hill Street.The Doctor of Pimlico | William Le Queux
Suffering from paralysis for years previous, his mental energy, as a chronic invalid, was amazing.The Philippine Islands | John Foreman
It must not be that a man so good, so kind, so altogether faithful to us all should be an invalid forever.Dorothy at Skyrie | Evelyn Raymond
British Dictionary definitions for invalid (1 of 2)
a person suffering from disablement or chronic ill health
(as modifier): an invalid chair
suffering from or disabled by injury, sickness, etc
to cause to become an invalid; disable
(usually foll by out; often passive) mainly British to require (a member of the armed forces) to retire from active service through wounds or illness
- invalidity, noun
British Dictionary definitions for invalid (2 of 2)
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
- invalidity (ˌɪnvəˈlɪdɪtɪ) or invalidness, noun
- invalidly, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012