Synonyms of invalid

invalid 1 of 3

adjective (1)

ˈin-və-ləd 

as in fragile

chronically or repeatedly suffering from poor health

an old and now invalid woman who rarely gets out anymore

Synonyms & Similar Words

• fragile
• weak
• weakly
• sickly
• dying
• sick
• frail
• ailing
• feeble
• 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
• misguided
• unconsidered
• random
• sophistic
• insane
• nonsensical
• asinine
• unconvincing
• ill-advised
• disorganized
• surreal
• inexplicable
• preposterous
• mad
• disordered
• eristic
• half-baked
• wacky
• unaccountable
• unexplainable
• nutty
• 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
• nonvalid
• inconsistent
• illogical
• weak
• wrong
• fallacious
• meaningless
• untenable
• unconscionable
• implausible
• unsound
• unconvincing
• foundationless
• specious
• stupid
• misled
• gratuitous
• flimsy
• nonlogical
• foolish
• uncalled-for
• silly
• unwise
• nonsensical
• insane
• fatuous
• asinine
• ill-advised
• mad
• preposterous
• wacky
• simpleminded
• 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

Related 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

Dissimilar Words

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

Example Sentences

Recent Examples of invalid

Adjective

But he was kept off the March 2024 ballot after Russia’s Supreme Court ruled that more than 9,000 signatures submitted by his campaign were invalid — enough to disqualify him. — ABC News, 3 Aug. 2026

Asylum cases must be filed within a year of entry in the country, and an invalid claim could lead to deportation proceedings. — Itzel Luna, Los Angeles Times, 31 July 2026

Verb

If this is ascertained, the BBC quotes an LA attorney saying this would render Hackman’s will invalid, and mean his children could have a claim to the estate. — Caroline Frost, Deadline, 16 Mar. 2025

DeSantis's office has said all options are on the table for their fight, but a legal ruling invaliding the agreement that currently gives Disney near-total control of the district would be the easiest resolution for the governor's headache. — Jack Birle, Washington Examiner, 8 Apr. 2023