tight-fitting vs skinny

tight-fitting is not a noun while skinny is a noun.

Word	Noun	Adjective	Verb	Adverb
tight-fitting	No	Yes	No	No
skinny	Yes	Yes	No	No

As adjectives, tight-fitting and skinny are synonyms defined as:

Other synonyms of tight-fitting include tight fitting, tightfitting, tightly fitting.

tight-fitting (noun)	skinny (noun)
	confidential information about a topic or person

tight-fitting (adjective)	skinny (adjective)
fitting snugly	of or relating to or resembling skin
	giving or spending with reluctance
	being very thin
	fitting snugly