hypnagogic (adj.)youdaoicibaDictYouDict[hypnagogic 词源字典]
1868, from French hypnagogique, from Greek hypnos "sleep" (see somnolence) + agogos "leading" (see act). Etymologically, "inducing sleep," but used mostly with a sense "pertaining to the state of consciousness when falling asleep."[hypnagogic etymology, hypnagogic origin, 英语词源]