View synonyms for unheard-of


[ uhn-hurd-uhv, -ov, -uhv ]


  1. that was never heard of; unknown:

    an unheard-of artist.

  2. such as was never known before; unprecedented:

    an unheard-of salary.

  3. shocking or outrageous:

    unheard-of conduct.



  1. previously unknown

    an unheard-of actress

  2. without precedent

    an unheard-of treatment

  3. highly offensive

    unheard-of behaviour

“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

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Word History and Origins

Origin of unheard-of1

First recorded in 1585–95
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Idioms and Phrases

Very unusual, extraordinary, as in It's unheard of to have all one's money refunded two years after the purchase . This expression alludes to a circumstance so unusual that it has never been heard of. [Late 1500s]
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Example Sentences

For one, she admitted TV documentary crews into her palaces to film her, an unheard-of relaxation of the court protocols.

Taymor and his business partner, Ashleigh Parsons, signed the lease and opened Alma an unheard-of two weeks later.

The low viral load was a very unusual but not unheard-of finding, meaning we may never know the truth.

We know it has given unheard-of power to anyone with a browser.

How can one not pay tribute to the unheard-of tenacity he demonstrated during every stage of this war?

This unheard-of despotism, this horrible political perjury, was certainly not merited by the good and generous Brazil.

Miriam vows to devour an unheard-of number of biscuits, too.

Here have I been striving with unheard-of patience to teach you and you have not hitherto been able to say your letters even.

This last action of unheard-of boldness literally staggered the mutineers.

In the act of sinking, a most extraordinary and unheard-of thing happened.


Definitions and idiom definitions from Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.