unmask vs mask

unmask is not a noun while mask is a noun.

Word	Noun	Adjective	Verb	Adverb
unmask	No	No	Yes	No
mask	Yes	No	Yes	No

unmask (noun)	mask (noun)
	activity that tries to conceal something
	a covering to disguise or conceal the face
	a protective covering worn over the face
	a party of guests wearing costumes and masks

unmask (verb)	mask (verb)
reveal the true nature of	put a mask on or cover with a mask
take the mask off	shield from light
	cover with a sauce
	hide under a false appearance
	make unrecognizable