unevenness vs uneven

unevenness is a noun but uneven is not a noun.

Word	Noun	Adjective	Verb	Adverb
unevenness	Yes	No	No	No
uneven	No	Yes	No	No

unevenness (noun)	uneven (noun)
the quality of being uneven and lacking uniformity
the quality of being unbalanced

unevenness (adjective)	uneven (adjective)
	not even or uniform as e.g. in shape or texture
	not divisible by two
	lacking consistency
	(of a contest or contestants) not fairly matched as opponents
	variable and recurring at irregular intervals