from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Occurring or existing without the knowledge of; unknown: a crisis unbeknown to us.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. not beknown
from the GNU version of the Collaborative International Dictionary of English
- adj. Not known; unknown.
from The Century Dictionary and Cyclopedia
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adv. without someone's knowledge
- adj. (usually used with `to') occurring or existing without the knowledge of
un-1 + obsolete beknown, known (from Middle English beknowen, past participle of beknowen, to get to know, from Old English becnāwan : be-, be- + cnāwan, to know; see know).(American Heritage® Dictionary of the English Language, Fourth Edition)
Back-formation of unbeknownst. (Wiktionary)