unbeknownst to (one)

unbeknownst to (one)

With someone being unaware (of something). Unbeknownst to Jacobson, the other two partners had drawn up the deal in such a way that they would have full control of the company in two years' time. My wife invited her entire family to come stay with us for Christmas—unbeknownst to me.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
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