work clothes vs overall

work clothes and overall both are nouns.

Word	Noun	Adjective	Verb	Adverb
work clothes	Yes	No	No	No
overall	Yes	Yes	No	No

As nouns, overall is a hyponym of work clothes; that is, overall is a word with a more specific, narrower meaning than work clothes:

work clothes: clothing worn for doing manual labor
overall: (usually plural) work clothing consisting of denim trousers (usually with a bib and shoulder straps)

work clothes (noun)	overall (noun)
clothing worn for doing manual labor	(usually plural) work clothing consisting of denim trousers (usually with a bib and shoulder straps)
	a loose protective coverall or smock worn over ordinary clothing for dirty work

work clothes (adjective)	overall (adjective)
	involving only main features
	including everything