sturdy vs sturdiness

sturdy is not a noun while sturdiness is a noun.

Word	Noun	Adjective	Verb	Adverb
sturdy	No	Yes	No	No
sturdiness	Yes	No	No	No

sturdy (noun)	sturdiness (noun)
	the property of something that is strongly built
	resoluteness evidenced by strength of character
	the state of being vigorous and robust

sturdy (adjective)	sturdiness (adjective)
not making concessions
having rugged physical strength; inured to fatigue or hardships
substantially made or constructed