/ Dictionary / Index U unbeknown: Meaning and Definition of Find definitions for: un•be•known Pronunciation: (un"bi-nōn'), [key] — adj. unknown; unperceived; without one's knowledge (usually fol. by to). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: unbeknown (Thesaurus) unbegotten unbelief Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language