[uhn-bi-lee-vuh-buh l]


too dubious or improbable to be believed: an unbelievable excuse.
so remarkable as to strain credulity; extraordinary: the unbelievable fury of the storm; an unbelievable athlete.

Origin of unbelievable

1540–50; un-1 + believable
Related formsun·be·liev·a·bly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for unbelievable

Contemporary Examples of unbelievable

Historical Examples of unbelievable

  • What a strange night it had been for Hester—more like some unbelievable romance!

    Weighed and Wanting

    George MacDonald

  • Out of her presence what I had seen was unthinkable, unbelievable.

  • If Danny was right he had no words to fit the unbelievable truth.

    The Hammer of Thor

    Charles Willard Diffin

  • The idea that she should even think of marrying a play-actor was unbelievable.

    The Portygee

    Joseph Crosby Lincoln

  • Outside the south windows he witnessed an unbelievable thing.

British Dictionary definitions for unbelievable



unable to be believed; incredible or astonishing
Derived Formsunbelievability or unbelievableness, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for unbelievable

1540s, from un- (1) "not" + believable. Related: Unbelievably.

Online Etymology Dictionary, © 2010 Douglas Harper