gynaecologist vs specialist

gynaecologist and specialist both are nouns.

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

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

Other hypernyms of gynaecologist include medical specialist.

gynaecologist (noun)	specialist (noun)
a specialist in gynecology	an expert who is devoted to one occupation or branch of learning
	practices one branch of medicine