neurologist vs specialist

neurologist and specialist both are nouns.

Word	Noun	Adjective	Verb	Adverb
neurologist	Yes	No	No	No
specialist	Yes	No	No	No

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

neurologist: a medical specialist in the nervous system and the disorders affecting it
specialist: practices one branch of medicine

Other hypernyms of neurologist include medical specialist.

neurologist (noun)	specialist (noun)
a medical specialist in the nervous system and the disorders affecting it	an expert who is devoted to one occupation or branch of learning
	practices one branch of medicine