'unbeknownst' definitions:

Without someone's knowledge; "unbeknownst to me, she made all the arrangements" [syn: unbeknown, unbeknownst]

(usually used with `to') occurring or existing without the knowledge of; "a crisis unbeknown to me"; "she had been ill for months, unbeknownst to the family" [syn: unbeknown(p), unbeknownst(p)]