brush up vs round off

brush up and round off both are verbs.

Word	Noun	Adjective	Verb	Adverb
brush up	No	No	Yes	No
round off	No	No	Yes	No

As verbs, brush up and round off are synonyms defined as:

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

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

brush up (verb)	round off (verb)
bring to a highly developed, finished, or refined state	express as a round number
refresh one's memory	make round
	bring to a highly developed, finished, or refined state