unbeknown

Twenty-year-old Tiller is supposed to be in college on an overseas program, but unbeknown to his dad, he has spent the last few months on a series of bizarre adventures in Asia.

From which illustration I inferred that Mr. Lincoln wanted Davis to escape, "unbeknown" to him.

I inclose to you a tin pound note, which ye father sends to ye unbeknown to me.

Perhaps he was skeptical of his country's harboring such a rare beauty unbeknown to him.

Then she flew from the castle and donned her catskin robe again, and slipped into the scullery again, unbeknown to the cook.

Without one moment's warning, and unbeknown even to her husband, the lady went to the station and entered the train for New York.