[英英辞典]
Merriam-Webster’s Word of the Day for June 30, 2007 is:
unbeknownst • \un-bih-NOHNST\ • adjective
: happening or existing without the knowledge of someone specified
Example sentence:
Unbeknownst to Clarice, we had been planning a surprise baby shower for her for weeks.
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.