unheard-of

unheard-of
adjective
previously unknown
especially : UNPRECEDENTED
moving at unheard-of speeds

Synonyms
fresh
new
novel
original
strange
unaccustomed
unfamiliar
unknown
unprecedented

Examples of unheard-of in a Sentence
Recent Examples on the Web
In a crushing defeat Thursday, a handful of Republican hardliners blocked a typically popular defense bill from advancing — the second time this week it was set back, an unheard-of loss for a House speaker.
—Lisa Mascaro, Fortune, 22 Sep. 2023
Its innovative approach leverages data analysis and demand prediction to transform retail operations, bringing unheard-of efficiencies to the entire process.
—Hilary Tetenbaum, USA TODAY, 6 Sep. 2023
Riding of deer by the monkeys of Yakushima Island is rare, but not unheard-of.
—Alan Taylor, The Atlantic, 31 Aug. 2023
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These examples are programmatically compiled from various online sources to illustrate current usage of the word 'unheard-of.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History
First Known Use
1592, in the meaning defined above

Time Traveler
The first known use of unheard-of was in 1592
See more words from the same year

Dictionary Entries Near unheard-of
unheard

unheard-of

unhearing


MLA
“Unheard-of.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unheard-of. Accessed 14 Oct. 2023.

Kids Definition
unheard-of

adjective

previously unknown : UNPRECEDENTED
moving at unheard-of speeds