unbeknownst

Adjective unbeknownst has 1 sense

• unbeknownst(s = adj.all) unbeknown - (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"

Adverbial unbeknownst has 1 sense

• unbeknownst(r = adv.all) unbeknown - without someone's knowledge; "unbeknownst to me, she made all the arrangements"