finish up vs cap off

finish up and cap off both are verbs.

Word	Noun	Adjective	Verb	Adverb
finish up	No	No	Yes	No
cap off	No	No	Yes	No

As verbs, cap off is a hyponym of finish up; that is, cap off is a word with a more specific, narrower meaning than finish up:

finish up (verb)	cap off (verb)
finish a task completely	finish or complete, as with some decisive action
finally be or do something