smoothen vs gloss

smoothen is not a noun while gloss is a noun.

Word	Noun	Adjective	Verb	Adverb
smoothen	No	No	Yes	No
gloss	Yes	No	Yes	No

As verbs, gloss is a hyponym of smoothen; that is, gloss is a word with a more specific, narrower meaning than smoothen:

Other hyponyms of smoothen include Simonise, Simonize, sleek, slick, buff, burnish, furbish.

smoothen (noun)	gloss (noun)
	the property of being smooth and shiny
	an outward or token appearance or form that is deliberately misleading
	an explanation or definition of an obscure word in a text
	an alphabetical list of technical terms in some specialized field of knowledge; usually published as an appendix to a text on that field

smoothen (verb)	gloss (verb)
become smooth	provide an interlinear translation of a word or phrase
make smooth or smoother, as if by rubbing	provide interlinear explanations for words or phrases
make (a surface) shine	give a deceptive explanation or excuse for
	give a shine or gloss to, usually by rubbing