The Collaborative International Dictionary of English v.0.48:
Omniscience \Om*nis"cience\, n. [Cf. F. omniscience.] The quality or state of being omniscient; the quality of knowing everything; -- an attribute peculiar to God. --Dryden. [1913 Webster]WordNet (r) 3.0 (2006):
omniscience n 1: the state of being omniscient; having infinite knowledge