odour vs sweetness

odour and sweetness both are nouns.

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

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

odour (noun)	sweetness (noun)
any property detected by the olfactory system	the property of tasting as if it contains sugar
the sensation that results when olfactory receptors in the nose are stimulated by particular chemicals in gaseous form	a pleasingly sweet olfactory property
	the quality of giving pleasure
	the taste experience when sugar dissolves in the mouth