dispatch vs polish off

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

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

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

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

dispatch (noun)	polish off (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)

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