Dr. vs physician

Dr. and physician both are nouns.

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

As nouns, Dr. and physician are synonyms defined as:

Other synonyms of Dr. include doc, doctor, MD, medico.

Dr. (noun)	physician (noun)
a licensed medical practitioner	a licensed medical practitioner
a person who holds Ph.D. degree (or the equivalent) from an academic institution