Source : Webster's Revised Unabridged Dictionary (1913)

Omniscient \Om*nis"cient\, a. [Omni- + L. sciens, -entis, p. pr.
   of scire to know: cf. F. omniscient. See {Science}.]
   Having universal knowledge; knowing all things; infinitely
   knowing or wise; as, the omniscient God. --
   {Om*nis"cient*ly}, adv.

         For what can scape the eye Of God all-seeing, or
         deceive his heart Omniscient?            --Milton.