/ Dictionary / Index U unreasonable: Meaning and Definition of Find definitions for: un•rea•son•a•ble Pronunciation: (un-rē'zu-nu-bul, -rēz'nu-), [key] — adj. not reasonable or rational; acting at variance with or contrary to reason; not guided by reason or sound judgment; irrational: an unreasonable person. not in accordance with practical realities, as attitude or behavior; inappropriate: His Bohemianism was an unreasonable way of life for one so rich. excessive, immoderate, or exorbitant; unconscionable: an unreasonable price; unreasonable demands. not having the faculty of reason. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: unreasonable (Thesaurus) unreason unreasoning Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language