left-handed vs left-handedness

left-handed is not a noun while left-handedness is a noun.

Word	Noun	Adjective	Verb	Adverb
left-handed	No	Yes	No	No
left-handedness	Yes	No	No	No

left-handed (noun)	left-handedness (noun)
	preference for using the left hand
	the status of being born of a morganatic marriage

left-handed (adjective)	left-handedness (adjective)
using or intended for the left hand
ironically ambiguous
rotating to the left
lacking physical movement skills, especially with the hands
(of marriages) of a marriage between one of royal or noble birth and one of lower rank; valid but with the understanding that the rank of the inferior remains unchanged and offspring do not succeed to titles or property of the superior
(of marriages) illicit or informal