from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Unbeknown.
- adv. Without the knowledge of a specified party. Used with to: Our cousin had been ill for years, unbeknownst to the family.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adv. without the knowledge of
from The Century Dictionary and Cyclopedia
- Same as unbeknown.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. (usually used with `to') occurring or existing without the knowledge of
- adv. without someone's knowledge
unbeknown + -st (as in amongst).(American Heritage® Dictionary of the English Language, Fourth Edition)
C. 1636: unusual form of un- + beknown (Wiktionary)