professor

noun

1. The most senior rank for an academic at a university or similar institution.

   “Professor is what you become after teaching for twenty to thirty years.”

2. (Philippines, US, informal)A teacher or faculty member at a college or university regardless of formal rank.
3. (archaic)One who professes something, such as a religious doctrine.

   “[…] I alvvayes thought / It vvas both impious and vnnaturall, / That ſuch immanity and bloody ſtrife / Should reigne among Profeſſors of one Faith.”

   “As for Religion, I have not said, much lesse meant irreverently of it, or of the Professors thereof.”

   “This period in which Abraham the Jew lived was one in which Magic was almost universally believed in, and in which its Professors were held in honour;”

4. (obsolete)A practitioner, one who (publicly) practises or teaches an art or skill.
5. (US, slang)A pianist in a saloon, brothel, etc.

   “You could hear […] pianos under the hands of whorehouse professors sounding like they came with keys between the keys.”

6. The puppeteer who performs a Punch and Judy show; a Punchman.
7. The title for someone who holds the job of professor.
8. (derogatory, informal, sometimes)A mock title for a person seen as pedantic or obsessive on a topic.

   “This is just what I wanted. I got professor environment pants over here, and I can't get my jetski started. How am I gonna get back?”