skinniness vs scrawniness

skinniness and scrawniness both are nouns.

Word	Noun	Adjective	Verb	Adverb
skinniness	Yes	No	No	No
scrawniness	Yes	No	No	No

As nouns, skinniness and scrawniness are synonyms defined as:

skinniness (noun)	scrawniness (noun)
the bodily property of lacking flesh	the bodily property of lacking flesh
	the property of being stunted and inferior in size or quality