round off vs brush up

round off and brush up both are verbs.

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

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

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

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

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