Regius professor vs professor

Regius professor and professor both are nouns.

Word	Noun	Adjective	Verb	Adverb
Regius professor	Yes	No	No	No
professor	Yes	No	No	No

As nouns, professor is a hypernym of Regius professor; that is, professor is a word with a broader meaning than Regius professor:

Regius professor: holder of a British professorship created by a royal patron
professor: someone who is a member of the faculty at a college or university

Other hypernyms of Regius professor include prof.

Regius professor (noun)	professor (noun)
holder of a British professorship created by a royal patron	someone who is a member of the faculty at a college or university