Dr. vs scholar

Dr. and scholar both are nouns.

Word	Noun	Adjective	Verb	Adverb
Dr.	Yes	No	No	No
scholar	Yes	No	No	No

As nouns, scholar is a hypernym of Dr.; that is, scholar is a word with a broader meaning than Dr.:

Dr.: a person who holds Ph.D. degree (or the equivalent) from an academic institution
scholar: a learned person; someone who by long study has gained mastery in one or more disciplines

Other hypernyms of Dr. include bookman, scholarly person.

Dr. (noun)	scholar (noun)
a licensed medical practitioner	a learned person; someone who by long study has gained mastery in one or more disciplines
a person who holds Ph.D. degree (or the equivalent) from an academic institution	someone (especially a child) who learns (as from a teacher) or takes up knowledge or beliefs
	a student who holds a scholarship