skinny vs tightly fitting

skinny is a noun but tightly fitting is not a noun.

Word	Noun	Adjective	Verb	Adverb
skinny	Yes	Yes	No	No
tightly fitting	No	Yes	No	No

As adjectives, skinny and tightly fitting are synonyms defined as:

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

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

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