The story
- Latin · derived fromprofessor“declarer, person who claims knowledge”
- Anglo-Norman · derived fromproffessur
- Middle English · inherited fromprofessor, professour
- English todayprofessor
From Middle English professor, professour, from Anglo-Norman proffessur and its etymon Latin professor (“declarer, person who claims knowledge”), from the past participle stem of profiteor (“profess”). By surface analysis, profess + -or.
Etymology from Wiktionary, CC BY-SA 4.0.