invalid

1 of 4

adjective (1)

in·​val·​id (ˌ)in-ˈva-ləd 

: not valid:

a

: being without foundation or force in fact, truth, or law

an invalid assumption

declared the will invalid

b

: logically inconsequent

invalidly

(ˌ)in-ˈva-ləd-lē 

adverb

invalid

2 of 4

noun

in·​va·​lid ˈin-və-ləd 

 British usually  -ˌlēd

: one who is sickly or disabled

invalid

3 of 4

verb

in·​va·​lid ˈin-və-ləd 

-ˌlid,

 British usually  -ˌlēd,

 or  ˌin-və-ˈlēd

invalided; invaliding; invalids

transitive verb

1

: to remove from active duty by reason of sickness or disability

2

: to make sickly or disabled

invalid

4 of 4

adjective (2)

in·​va·​lid ˈin-və-ləd 

 British usually  -ˌlēd

1

: affected by disease or disability : sickly

2

: of, relating to, or suited to one that is sick

an invalid chair

Synonyms

Adjective (1)

• bad
• inoperative
• nonbinding
• nonvalid
• nugatory
• null
• null and void
• void

Adjective (2)

• ailing
• sickly
• weakly

Example Sentences

Noun

Her husband has become an invalid.

Recent Examples on the Web

Adjective

The Marvell-Elaine plaintiffs argued in the lawsuit that the LEARNS Act emergency clause was invalid. —Cynthia Howell, Arkansas Online, 27 May 2023

Another significant element of the changes is known as the override clause, which would give the Israeli parliament the power to pass laws previously ruled invalid by the court, essentially overriding Supreme Court decisions. —Hadas Gold, CNN, 25 Mar. 2023

For instance, movement within the phantom can introduce uncertainty into the experiment, and inaccurate probe placement can lead to invalid results. —IEEE Spectrum, 20 Jan. 2023

In the days leading up to the election, Benson blasted a legal bid by Karamo that initially asked a court to declare tens of thousands of Detroit absentee ballots invalid. —Detroit Free Press, 9 Nov. 2022

She was questioned for less than an hour and then released when detectives decided—incorrectly—that the warrant was invalid. —Ian Parker, The New Yorker, 7 Nov. 2022

At issue is whether to uphold a preliminary ruling from a federal judge in Texas, who declared in April that the Food and Drug Administration’s 23-year-old approval of the pill, mifepristone, was invalid. —Abbie Vansickle And Pam Belluck, BostonGlobe.com, 17 May 2023

Gilead, however, contended that the CDC’s patents were invalid and won a separate federal court ruling that the government breached contracts over research. —Daniel Gilbert, Washington Post, 9 May 2023

But since the pandemic began, Peleseuma has been repeatedly confronted with an additional invalid form of identification: People keep trying to get into the bar by showing him a photo of their ID on their phone. —Esther Mobley, San Francisco Chronicle, 10 Apr. 2023

Noun

As these invalids made their way to Portsmouth, nearly half slipped away, including one who hobbled off on a wooden leg. —David Grann, The New Yorker, 28 Feb. 2023

Five hundred invalids from the Royal Hospital in Chelsea, many in their 60s and 70s, were ordered to fill out the ranks. —Mary Ann Gwinn, Los Angeles Times, 14 Apr. 2023

In 1944, Marta’s parents, Rudolf Beck, aged seventy, and Regina, a chronic invalid at sixty-nine, died at Auschwitz. —Andrew O’hagan, The New York Review of Books, 13 Apr. 2021

See More

Word History

Etymology

Adjective (1)

Latin invalidus weak, from in- + validus strong — more at valid

Adjective (2)

Latin & French; French invalide, from Latin invalidus

First Known Use

Adjective (1)

1542, in the meaning defined above

Noun

1701, in the meaning defined above

Verb

1787, in the meaning defined at sense 1

Adjective (2)

1642, in the meaning defined at sense 1

Kids Definition

invalid

1 of 4 adjective

in·​val·​id (ˈ)in-ˈval-əd 

: having no force or effect : not valid

an invalid parking sticker

an invalid assumption

invalidity

ˌin-və-ˈlid-ət-ē

noun

invalidly

(ˈ)in-ˈval-əd-lē 

adverb

invalid

2 of 4 adjective

in·​va·​lid ˈin-və-ləd 

1

: suffering from disease or disability : sickly

2

: of, relating to, or suited to an invalid

invalid

3 of 4 noun

like ²

 

: one who is sickly or disabled

invalid

4 of 4 verb

in·​va·​lid ˈin-və-ləd 

-ˌlid

: to make sickly or disabled

Etymology

Adjective

from earlier invalid "not having a sound basis in fact or reason, not valid," from Latin invalidus "weak"

Adjective

from French invalide "suffering from a disease, sickly," from Latin invalidus "weak"

Medical Definition

invalid

1 of 3 adjective

in·​va·​lid

ˈin-və-ləd, British usually -ˌlēd

1

: affected by disease or disability : sickly

2

: of, relating to, or suited to one that is sick

an invalid chair

invalid

2 of 3 noun

: one who is sickly or disabled

invalid

3 of 3 transitive verb

in·​va·​lid

ˈin-və-ləd, -ˌlid, British usually -ˌlēd or ˌin-və-ˈlēd

1

: to remove from active duty by reason of sickness or disability

was invalided out of the army

2

: to make sickly or disabled

a patient invalided by valvular disease

Legal Definition

invalid

adjective

in·​val·​id in-ˈva-ləd 

: being without force or effect under the law

declared the will invalid

invalidly adverb