[uhn-hurd-uhv, -ov, -uh v]
- 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. 2018
- previously unknownan unheard-of actress
- without precedentan unheard-of treatment
- highly offensiveunheard-of behaviour
Idioms and Phrases with unheard of
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]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.