unreasonable

Synonyms: absurd all wet arbitrary biased capricious contradictory erratic fallacious far-fetched foolish full of hot air headstrong illogical incoherent incongruous inconsequential inconsistent invalid irrational loose mad nonsensical off the wall opinionated preposterous quirky reasonless senseless silly stupid thoughtless unreasoned vacant wrong

Antonyms: logical practical pragmatic realistic reasonable sensible

Synonyms: absonant arbitrary costing an arm and a leg dear excessive exorbitant extortionate extreme far-out illegitimate immoderate improper inordinate intemperate out of bounds overkill overmuch peremptory posh pricey senseless steep stiff too great too much too-too uncalled-for unconscionable undue unfair unjust unjustifiable unlawful unrightful unwarrantable unwarranted up to here way out wrongful

Antonyms: cheap economical low plain reasonable