round off vs polish

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

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

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

round off and polish: bring to a highly developed, finished, or refined state

Other synonyms of round off include brush up, polish up, round.

round off (noun)	polish (noun)
	the property of being smooth and shiny
	a highly developed state of perfection; having a flawless or impeccable quality
	a preparation used in polishing

round off (verb)	polish (verb)
express as a round number	bring to a highly developed, finished, or refined state
make round	improve or perfect by pruning or polishing
bring to a highly developed, finished, or refined state	make (a surface) shine