Meaning of DRIFT OFF

WordNet Dictionary
	Definition:		[v]  change from a waking to a sleeping state; "he always falls asleep during lectures"
	Synonyms:		dope off, doze off, drop off, drowse off, fall asleep, flake out, nod off
	Antonyms:		arouse, awake, awaken, come alive, wake, wake up, waken
	See Also:		zonk out