Entry 3 senses · 2 variants Webster, 1913 Unknow · Un·know · IPA v. t. a. 01 v. t. To cease to know; to lose the knowledge of. 1. To cease to know; to lose the knowledge of.[Obs.] 2. To fail of knowing; to be ignorant of.[Obs.] 02 a. Unknown. 1. Unknown.[Obs.]