round off vs purse

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

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

As verbs, purse is a hyponym of round off; that is, purse is a word with a more specific, narrower meaning than round off:

round off (noun)	purse (noun)
	a container used for carrying money and small personal items or accessories (especially by women)
	a small bag for carrying money
	a sum of money offered as a prize
	a sum of money spoken of as the contents of a money purse

round off (verb)	purse (verb)
express as a round number	contract one's lips into a rounded shape
make round	gather or contract into wrinkles or folds; pucker
bring to a highly developed, finished, or refined state