polish off vs dispatch

polish off is not a noun while dispatch is a noun.

Word	Noun	Adjective	Verb	Adverb
polish off	No	No	Yes	No
dispatch	Yes	No	Yes	No

As verbs, polish off and dispatch are synonyms defined as:

Other synonyms of polish off include bump off, hit, murder, off, remove, slay.

polish off (noun)	dispatch (noun)
	the act of sending off something
	killing a person or animal
	the property of being prompt and efficient
	an official report (usually sent in haste)

polish off (verb)	dispatch (verb)
finish a task completely	kill without delay
finish eating all the food on one's plate or on the table	send away towards a designated goal
kill intentionally and with premeditation	complete or carry out
	kill intentionally and with premeditation
	dispose of rapidly and without delay and efficiently