Hypnagogic [hip-nə-GAH-jik]  

Part of speech: adjective 

Origin: French, late 19th century  

1. Relating to the state immediately before falling asleep.  

Examples of hypnagogic in a sentence  

"He listened to instrumental music to relax into a hypnagogic state."  

"My grandmother always told me warm milk was hypnagogic, but I've never felt sleepy after drinking it."