sleep late vs sleep

sleep late is not a noun while sleep is a noun.

Word	Noun	Adjective	Verb	Adverb
sleep late	No	No	Yes	No
sleep	Yes	No	Yes	No

As verbs, sleep is a hypernym of sleep late; that is, sleep is a word with a broader meaning than sleep late:

Other hypernyms of sleep late include catch some Z's, kip, log Z's, slumber.

sleep late (noun)	sleep (noun)
	a natural and periodic state of rest during which consciousness of the world is suspended
	euphemisms for death (based on an analogy between lying in a bed and in a tomb)
	a torpid state resembling deep sleep
	a period of time spent sleeping

sleep late (verb)	sleep (verb)
sleep later than usual or customary	be asleep
	be able to accommodate for sleeping