split up vs part

split up and part both are nouns.

Word	Noun	Adjective	Verb	Adverb
split up	Yes	No	Yes	No
part	Yes	No	Yes	Yes

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

Other hypernyms of split up include break, break up, separate, split, split up.

As verbs, split up and part are synonyms defined as:

split up and part: discontinue an association or relation; go different ways

Other synonyms of split up include break, break up, separate, split.

split up (noun)	part (noun)
an increase in the number of outstanding shares of a corporation without changing the shareholders' equity	the actions and activities assigned to or required or expected of a person or group
	the effort contributed by a person in bringing about a result
	something less than the whole of a human artifact
	an item that is an instance of some type
	a line of scalp that can be seen when sections of hair are combed in opposite directions
	one of the portions into which something is regarded as divided and which together constitute a whole
	an actor's portrayal of someone in a play
	that which concerns a person with regard to a particular role or situation
	the melody carried by a particular voice or instrument in polyphonic music
	the extended spatial location of something
	a portion of a natural object
	assets belonging to or due to or contributed by an individual person or group
	something determined in relation to something that includes it

split up (verb)	part (verb)
become separated into pieces or fragments	move or break apart
get a divorce; formally terminate a marriage	force, take, or pull apart
discontinue an association or relation; go different ways	depart for someplace
separate into parts or portions	go one's own way; move apart
	discontinue an association or relation; go different ways

split up (adverb)	part (adverb)
	to some extent; in some degree; not wholly