hypnagogic \hip-nuh-GOJ-ik; -GOH-jik\, adjective:

Of, pertaining to, or occurring in the state of drowsiness preceding sleep.

Hypnagogic (sometimes spelled hypnogogic) ultimately derives from Greek hupnos, "sleep" + agogos, "leading," from agein, "to lead."

His uncensored and uncensoring subconscious allows him to absorb the world around him and in him, and to spit it out almost undigested, as if he were walking around in a constant hypnagogic state.

-- Susan Bolotin, "Don't Turn Your Back on This Book", New York Times, June 9, 1985