Synonyms of unreasonable

unreasonable

adjective

ˌən-ˈrēz-nə-bəl

1

as in unwarranted

having no basis in reason or fact

an unreasonable assumption

Synonyms & Similar Words

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

Antonyms & Near Antonyms

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

2

as in irrational

not using or following good reasoning

an unreasonable respect for a man who did not deserve it

Synonyms & Similar Words

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

Antonyms & Near Antonyms

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

Example Sentences

Recent Examples of unreasonable

The surrogate must have previously given birth to at least one child, and a doctor must determine that another pregnancy wouldn’t pose an unreasonable risk to her or the baby. — Tiffani Jackson, Fort Worth Star-Telegram, 19 Aug. 2026

The Saturday order said that expecting LeVota’s attorneys to adequately prepare for trial before April would be unreasonable and that denying the request could interfere with his right to effective legal representation. — Ben Wheeler, Kansas City Star, 17 Aug. 2026

In her lawsuit, Phyllis Zorn said the raid violated protections for a free press, safeguards against unreasonable searches by law enforcement and a federal law that limits searches and seizures of journalists' materials. — Thao Nguyen, USA Today, 13 Aug. 2026

Given those pressures, a wholesale ban on AI is unreasonable, says Kathleen Schmidt, a publishing strategist who has worked in the industry for more than 30 years. — Cameron Pugh, Christian Science Monitor, 12 Aug. 2026