Source : Webster's Revised Unabridged Dictionary (1913)

Unknow \Un*know"\, v. t. [1st un- + know.]
   1. To cease to know; to lose the knowledge of. [Obs.]

   2. To fail of knowing; to be ignorant of. [Obs.]

Unknow \Un*know"\, a. [See Un- not, {Know}.]
   Unknown. [Obs.] ``French of Paris was to her unknow.''
   --Chaucer.