Synonyms of invalid

invalid 1 of 3

adjective (1)

ˈin-və-ləd 

as in weak

chronically or repeatedly suffering from poor health

an old and now invalid woman who rarely gets out anymore

Synonyms & Similar Words

• weak
• fragile
• weakly
• dying
• sickly
• frail
• sick
• ailing
• feeble
• lame
• challenged
• fading
• weakened
• incurable
• bedridden
• delicate
• incapacitated
• poorly
• moribund
• debilitated
• unhealthy
• unsound
• enfeebled
• infirm
• ill
• decrepit
• bedfast
• unwell
• indisposed
• worn-out
• peaked
• run-down

Antonyms & Near Antonyms

• well
• healthy
• whole
• sound
• wholesome
• fit
• hale
• hearty
• able-bodied
• well-conditioned

invalid

2 of 3

adjective (2)

(ˌ)in-ˈva-ləd 

1

as in null

having no legal or binding force

the treaty is invalid once one side violates it

Synonyms & Similar Words

• null
• void
• illegal
• inoperative
• null and void
• nugatory
• bad
• worthless
• useless
• nonvalid
• nonbinding
• ineffective
• ineffectual

Antonyms & Near Antonyms

• valid
• good
• legal
• binding
• working

2

as in erroneous

not being in agreement with what is true

that's an invalid assumption on your part

Synonyms & Similar Words

• erroneous
• incorrect
• inaccurate
• wrong
• false
• misleading
• untrue
• inexact
• unsound
• untruthful
• distorted
• off base
• off
• fraudulent
• deceptive
• specious
• spurious
• fictitious
• illusory
• fallacious
• counterfactual
• delusive
• dishonest
• deceitful
• unproven
• awry
• mendacious
• lying
• unconfirmed
• untested
• invented
• delusory
• amiss
• askew
• fabricated
• made-up
• trumped-up

Antonyms & Near Antonyms

• valid
• correct
• true
• proper
• right
• accurate
• exact
• sound
• precise
• factual
• confirmed
• demonstrated
• established
• tested
• errorless
• perfect
• veracious
• proven
• impeccable
• flawless
• faultless
• letter-perfect

3

as in unreasonable

not using or following good reasoning

an argument which has one untrue premise is invalid

Synonyms & Similar Words

• unreasonable
• irrational
• illegitimate
• unreasoning
• misleading
• weak
• illogical
• unreasoned
• absurd
• fallacious
• foolish
• silly
• unsound
• inconsequential
• meaningless
• inconsistent
• nonrational
• weird
• inconsequent
• unusual
• odd
• specious
• strange
• sophistical
• misguided
• unconsidered
• random
• sophistic
• insane
• nonsensical
• asinine
• unconvincing
• eristical
• ill-advised
• surreal
• disorganized
• inexplicable
• mad
• preposterous
• disordered
• eristic
• half-baked
• whacky
• unaccountable
• unexplainable
• nutty
• wacky
• senseless
• peculiar
• reasonless
• rambling
• Kafkaesque

Antonyms & Near Antonyms

• valid
• reasonable
• logical
• sound
• rational
• wise
• sensible
• sane
• justified
• informed
• sober
• reasoned
• enlightened
• well-founded
• just
• clear
• certain
• well-grounded
• solid
• plausible
• convincing
• true
• compelling
• organized
• persuasive
• sure
• credible
• commonsense
• ordered
• satisfying
• cogent
• confirmed
• demonstrated
• established
• validated
• substantiated
• corroborated

4

as in unsupported

having no basis in reason or fact

an invalid claim that can be easily disproved by the facts

Synonyms & Similar Words

• unreasonable
• unsupported
• unfounded
• baseless
• unwarranted
• unsubstantiated
• irrational
• false
• groundless
• unnecessary
• unreasoned
• absurd
• misleading
• inconsistent
• nonvalid
• illogical
• weak
• wrong
• fallacious
• meaningless
• untenable
• unconscionable
• implausible
• unsound
• unconvincing
• foundationless
• specious
• stupid
• misled
• gratuitous
• flimsy
• nonlogical
• foolish
• uncalled-for
• silly
• unwise
• insane
• nonsensical
• fatuous
• asinine
• ill-advised
• mad
• preposterous
• lunatic
• whacky
• simpleminded
• wacky
• harebrained
• nutty
• senseless
• crazy
• brainless
• crackpot
• half-witted

Antonyms & Near Antonyms

• valid
• reasonable
• good
• hard
• justified
• reasoned
• certified
• just
• confirmed
• logical
• validated
• well-founded
• rational
• true
• substantiated
• actual
• real
• informed
• wise
• well-grounded
• certain
• sensible
• verified
• genuine
• sane
• sure
• sober
• corroborated
• clear
• solid
• plausible
• sound
• compelling
• convincing
• persuasive
• credible
• satisfying
• commonsense
• cogent

invalid

3 of 3

verb

as in to impair

Synonyms & Similar Words

• impair
• hurt
• harm
• damage
• injure
• exhaust
• lay up
• grind (down)
• deplete
• wash out
• wear down
• wear out
• impoverish
• disable
• depress
• cripple
• unman
• hamstring
• break down
• incapacitate
• weaken
• paralyze
• waste
• enfeeble
• debilitate
• devitalize
• sap
• soften
• tire
• etiolate
• enervate
• prostrate

Antonyms & Near Antonyms

• strengthen
• fortify
• recruit
• beef (up)
• energize
• season
• rejuvenate
• harden
• invigorate
• vitalize
• toughen

Examples of invalid in a Sentence

Recent Examples on the Web

Adjective

When the secretary of state’s office certified the Green Party for the Ballot, the state Democratic Party challenged that decision, pointing out that the wrong form was used and that the signatures were therefore invalid. —Nina Totenberg, NPR, 20 Sep. 2024

But in an emergency motion filed Thursday, attorneys for Combs said the default judgment is invalid under Michigan state law because he was never served with the lawsuit and learned of it only after the judgment was reported by media outlets Monday. —Janelle Griffith, NBC News, 13 Sep. 2024

Still, state Supreme Court Justice Phil Berger Jr. — the Senate leader's son — argued in his concurring opinion that the existence of invalid ballots is concerning. —Lucille Sherman, Axios, 11 Sep. 2024

The relay, exploited on April 3rd, 2023, revealed block bodies to the malicious proposer even when an invalid block header was signed. —Gary Weinstein, Forbes, 8 Sep. 2024