Definition of unbeknownst
1 : happening or existing without the knowledge of someone specified —usually used with to unbeknownst to us rumors were flying
2 : unknown
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Examples of unbeknownst in a sentence
unbeknownst to me, my mother was planning a party
Did You Know?
Unbeknownst derives from beknown, an obsolete synonym of known. But for a word with a straightforward history, unbeknownst and its older and less common variant unbeknown have created quite a flap among usage commentators. Despite widespread use (including appearances in the writings of Charles Dickens, A.E. Housman, and E.B. White), the two words have been called everything from "obsolete" to "vulgar." Our evidence, however, shows that both can be considered standard.
Origin and Etymology of unbeknownst
1un- + obsolete English beknown known; unbeknownst, irregular from unbeknown
First Known Use: 1636
UNBEKNOWNST Defined for Kids
Seen and Heard
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