ear doctor vs specialist

ear doctor and specialist both are nouns.

Word	Noun	Adjective	Verb	Adverb
ear doctor	Yes	No	No	No
specialist	Yes	No	No	No

As nouns, specialist is a hypernym of ear doctor; that is, specialist is a word with a broader meaning than ear doctor:

Other hypernyms of ear doctor include medical specialist.

ear doctor (noun)	specialist (noun)
a physician who specializes in the ear and its diseases	an expert who is devoted to one occupation or branch of learning
	practices one branch of medicine