unheard-of

[ uhn-hurd-uhv, -ov, -uh v ]
/ ʌnˈhɜrdˌʌv, -ˌɒv, -əv /

adjective

that was never heard of; unknown: an unheard-of artist.
such as was never known before; unprecedented: an unheard-of salary.
shocking or outrageous: unheard-of conduct.

Origin of unheard-of

First recorded in 1585–95
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for unheard-of

British Dictionary definitions for unheard-of

unheard-of

adjective

previously unknownan unheard-of actress
without precedentan unheard-of treatment
highly offensiveunheard-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