slenderness vs slightness

slenderness and slightness both are nouns.

Word	Noun	Adjective	Verb	Adverb
slenderness	Yes	No	No	No
slightness	Yes	No	No	No

As nouns, slenderness and slightness are synonyms defined as:

Other synonyms of slenderness include slimness.

slenderness (noun)	slightness (noun)
the quality of being slight or inadequate	slenderness
the property of an attractively thin person	the property of an attractively thin person
relatively small dimension through an object as opposed to its length or width	the quality of being unimportant and petty or frivolous