pleasant vs sweetness

pleasant is not a noun while sweetness is a noun.

Word	Noun	Adjective	Verb	Adverb
pleasant	No	Yes	No	No
sweetness	Yes	No	No	No

pleasant (noun)	sweetness (noun)
	the property of tasting as if it contains sugar
	a pleasingly sweet olfactory property
	the quality of giving pleasure
	the taste experience when sugar dissolves in the mouth

pleasant (adjective)	sweetness (adjective)
affording pleasure; being in harmony with your taste or likings
(of persons) having pleasing manners or behavior