From Middle English unresonable; equivalent to un- + reason + -able.

• IPA: /ʌnˈɹiːz(ə)nəbl̩/

unreasonable

1. Without the ability to reason; unreasoning.
   • c. 1591–1595 (date written), William Shakespeare, “The Tragedie of Romeo and Ivliet”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC ↗, [Act III, scene iii]:

     Hold thy desperate hand:
     Art thou a man? thy form cries out thou art:
     Thy tears are womanish; thy wild acts denote
     The unreasonable fury of a beast:
     Unseemly woman in a seeming man!

2. Not reasonable; going beyond what could be expected or asked for.

   Antonyms: reasonable

   • 1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], →OCLC ↗, Acts 25:27 ↗:

     For it seemeth to me vnreasonable, to send a prisoner, and not withall to signifie the crimes laid against him.

   • 1791 (date written), Mary Wollstonecraft, “Duty to Parents”, in A Vindication of the Rights of Woman: With Strictures on Political and Moral Subjects, London: […] J[oseph] Johnson, […], published 1792, →OCLC ↗, page 358 ↗:

     The will of those who never allow their will to be disputed, unless they happen to be in a good humour, when they relax proportionally, is almost always unreasonable.

• French: déraisonnable
• German: unvernünftig, kompromisslos, nicht nachvollziehbar, unklug, übertrieben, unmäßig
• Italian: irragionevole
• Portuguese: insensato, (MAT) irracional
• Russian: неразу́мный
• Spanish: irrazonable