The Collaborative International Dictionary of English v.0.48:
Gnosis \Gno"sis\, n. [NL., fr. Gr. gnw^sis.] (Metaph.) The deeper wisdom; knowledge of spiritual truth, such as was claimed by the Gnostics. [1913 Webster]WordNet (r) 3.0 (2006):
gnosis n 1: intuitive knowledge of spiritual truths; said to have been possessed by ancient Gnostics