sit up vs wake

sit up is not a noun while wake is a noun.

Word	Noun	Adjective	Verb	Adverb
sit up	No	No	Yes	No
wake	Yes	No	Yes	No

As verbs, wake is a hypernym of sit up; that is, wake is a word with a broader meaning than sit up:

sit up (noun)	wake (noun)
	a vigil held over a corpse the night before burial
	the wave that spreads behind a boat as it moves forward
	the consequences of an event (especially a catastrophic event)

sit up (verb)	wake (verb)
not go to bed	be awake, be alert, be there
change to an upright sitting position	stop sleeping
	cause to become awake or conscious
	to alert someone to something
	arouse or excite feelings and passions