fashion designer vs clothes designer

fashion designer and clothes designer both are nouns.

Word	Noun	Adjective	Verb	Adverb
fashion designer	Yes	No	No	No
clothes designer	Yes	No	No	No

As nouns, fashion designer and clothes designer are synonyms defined as:

Other synonyms of fashion designer include couturier, designer.

fashion designer (noun)	clothes designer (noun)
someone who designs clothing	someone who designs clothing