operating surgeon vs MD

operating surgeon and MD both are nouns.

Word	Noun	Adjective	Verb	Adverb
operating surgeon	Yes	No	No	No
MD	Yes	No	No	No

As nouns, MD is a hypernym of operating surgeon; that is, MD is a word with a broader meaning than operating surgeon:

Other hypernyms of operating surgeon include doc, doctor, Dr., medico, physician.

operating surgeon (noun)	MD (noun)
a physician who specializes in surgery	a doctor's degree in medicine
	a Mid-Atlantic state; one of the original 13 colonies, with capital Annapolis
	a licensed medical practitioner