designer vs interior designer

designer and interior designer both are nouns.

Word	Noun	Adjective	Verb	Adverb
designer	Yes	No	No	No
interior designer	Yes	No	No	No

As nouns, designer and interior designer are synonyms defined as:

designer and interior designer: a person who specializes in interior design

designer (noun)	interior designer (noun)
someone who creates plans to be used in making something (such as buildings)	a person who specializes in interior design
someone who designs clothing
a person who specializes in interior design
a person who devises plots or intrigues
someone who specializes in graphic design