sleep.     25 Mar 2012    Hypnagogia Hypnagogia  (from  Greek   hypnos  "sleep" +  agōgos  "leading, inducing") is the transitional state between  wakefulness  and  sleep  (i.e., the  onset of sleep ), originally coined in adjectival form as "hypnagogic" by  Alfred Maury . [1] [2]   The equivalent transition to wakefulness