splinter vs split up

splinter and split up both are nouns.

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

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

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

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

Other hypernyms of splinter include carve up, dissever, divide, separate, split.

splinter (noun)	split up (noun)
a small thin sharp bit of wood or glass or metal	an increase in the number of outstanding shares of a corporation without changing the shareholders' equity

splinter (verb)	split up (verb)
break up into splinters or slivers	become separated into pieces or fragments
withdraw from an organization or communion	get a divorce; formally terminate a marriage
divide into slivers or splinters	discontinue an association or relation; go different ways
	separate into parts or portions