un·heard-of
| \ ˌən-ˈhərd-ˌəv
, -ˌäv \
, -ˌäv \
Definition of unheard-of
: previously unknown
especially
: unprecedented
moving at unheard-of speeds
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“Unheard-of.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unheard-of. Accessed 15 Jun. 2021.
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More Definitions for unheard-of
unheard-of
adjective
English Language Learners Definition of unheard-of
: not known to have existed or happened before : very unusual
See the full definition for unheard-of in the English Language Learners Dictionary
unheard-of
adjective
un·heard-of
| \ ˌən-ˈhərd-ˌəv, -ˌäv \
Kids Definition of unheard-of
: not known before
an unheard-of invention
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Time Traveler for unheard-of
The first known use of unheard-of was in 1592
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