southernness vs southern

southernness is a noun but southern is not a noun.

Word	Noun	Adjective	Verb	Adverb
southernness	Yes	No	No	No
southern	No	Yes	No	No

southernness (noun)	southern (noun)
the property of being to the south

southernness (adjective)	southern (adjective)
	situated in or coming from regions of the south
	in or characteristic of a region of the United States south of (approximately) the Mason-Dixon line
	from the south; used especially of wind
	situated in or oriented toward the south