Adjective unreasonable has 5 senses
  1. unreasonable - not reasonable; not showing good judgment
    reasonable, sensible, commonsense, commonsensible, commonsensical, healthy, intelligent, levelheaded, sound, logical, tenable, well-founded
  2. cockamamie, cockamamy, goofy, sappy, silly, wacky, whacky, zany, unreasonable - pungent adjectives of disesteem; "gave me a cockamamie reason for not going"; "wore a goofy hat"; "a silly idea"; "some wacky plan for selling more books"
    Antonym: wise (indirect, via foolish)
  3. unreasonable - absurd and inappropriate; "the unreasonable nimbus of romance with which she had encircled that man"- Thomas Hardy
    realistic (indirect, via unrealistic)
  4. excessive, inordinate, undue, unreasonable - beyond normal limits; "excessive charges"; "a book of inordinate length"; "his dress stops just short of undue elegance"; "unreasonable demands"
    Antonym: moderate (indirect, via immoderate)
  5. absurd, unreasonable - inconsistent with reason or logic or common sense; "the absurd predicament of seeming to argue that virtue is highly desirable but intensely unpleasant"- Walter Lippman
    Antonym: logical (indirect, via illogical)