unbeknown adj : (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)] adv : without someone's knowledge; "unbeknownst to me, she made all the arrangements" [syn: unbeknownst]

English

Adjective

1. Not beknown

able, enigmatic, incalculable, incognizable, mysterious, puzzling, sealed, strange, unapparent, unapprehended, unascertained, uncharted, unclassified, undisclosed, undiscoverable, undiscovered, undivulged, unexplained, unexplored, unexposed, unfamiliar, unfathomed, unheard, unheard-of, unidentified, uninvestigated, unknowable, unknown, unperceived, unplumbed, unrevealed, unsuspected, untouched, virgin