1. Pertaining to knowledge.
2. Possessing knowledge; especially, esoteric knowledge of spiritual matters.
3. When capitalized, pertaining to or characteristic of the Gnostics.
4. Of, relating to, or possessing intellectual or spiritual knowledge.

A member of any of certain sects among the early Christians who claimed to have superior knowledge of spiritual matters, and explained the world as created by powers or agencies arising as emanations from the Godhead.