He had a 'professorial' look to him. = He looked 'professorial'. [=he looked like a professor]
a chemistry/history 'professor' = a 'professor' of chemistry/history
(..) Timer: . Style: Default,Tahoma,- Format: Marked, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text Dialogue: Marked=..,Default,NTP,!Effect,l should've known that you would\Nbe here, Professor McGonagall. Dialogue: Marked=..,Default,NTP,!Effect,Good evening, Professor Dumbledore. Dialogue: Marked=..,Default,NTP,!Effect,Are the rumors true, Albus? Dialogue: Marked=..,Default,NTP,!Effect,l'm afraid so, professor.\NThe good and the bad. Dialogue: Marked=..,Default,NTP,!Effect,-And the boy?\N-Hagrid is bringing him. (..)2001 Harry Potter and the Sorcerer's Stone