finishing vs finis

finishing and finis both are nouns.

Word	Noun	Adjective	Verb	Adverb
finishing	Yes	No	No	No
finis	Yes	No	No	No

As nouns, finis is a hyponym of finishing; that is, finis is a word with a more specific, narrower meaning than finishing:

Other hyponyms of finishing include close, closing curtain, finale.

finishing (noun)	finis (noun)
the act of finishing	the concluding part of any performance
a decorative texture or appearance of a surface (or the substance that gives it that appearance)	the temporal end; the concluding time