hone vs round off

hone is a noun but round off is not a noun.

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

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

Other hyponyms of hone include optimise, optimize, brush up, polish, polish up, round.

hone (noun)	round off (noun)
a whetstone made of fine gritstone; used for sharpening razors
a tool consisting of a number of fine abrasive slips held in a machine head, rotated and reciprocated to impart a smooth finish to cylinder bores, etc.

hone (verb)	round off (verb)
make perfect or complete	express as a round number
sharpen with a hone	make round
	bring to a highly developed, finished, or refined state