also unbeknown adjective Etymology: 1un- + obsolete English beknown known; ~, irregular from unbeknown Date: 1636 happening or existing without the knowledge of someone specified, unknown
UNBEKNOWNST
Meaning of UNBEKNOWNST in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012