Collocations for professor - noun

distinguished, eminent
respected
a respected law professor at a prestigious university

absent-minded, eccentric, mad
He fitted perfectly the stereotype of the absent-minded professor.

college, university
adjunct, assistant, associate, full, junior, senior (all AmE)
tenured (esp. AmE)
research (esp. AmE)
a research professor at the University of Southern California

visiting
I spent six months as a visiting professor at Brown University.

retired
emerita (AmE), emeritus
Jennifer Bradbery, emeritus professor/professor emeritus of surgery (BrE)
Jennifer Bradbery, emerita professor/professor emerita of surgery (AmE)

history, law, etc.

professor of
an eminent professor of English