unctuous vs buttery

unctuous is not a noun while buttery is a noun.

Word	Noun	Adjective	Verb	Adverb
unctuous	No	Yes	No	No
buttery	Yes	Yes	No	No

As adjectives, unctuous and buttery are synonyms defined as:

unctuous and buttery: unpleasantly and excessively suave or ingratiating in manner or speech

Other synonyms of unctuous include fulsome, oily, oleaginous, smarmy, soapy.

unctuous (noun)	buttery (noun)
	a teashop where students in British universities can purchase light meals
	a small storeroom for storing foods or wines

unctuous (adjective)	buttery (adjective)
unpleasantly and excessively suave or ingratiating in manner or speech	resembling or containing or spread with butter
	unpleasantly and excessively suave or ingratiating in manner or speech