Matthew 23:10

καθηγητής. ‘A guide,’ then a dignified name for ‘a teacher,’ used in this sense by Plutarch of one who did not care to be called a παιδαγωγός and so adopted the more high-sounding title of καθηγητής· τροφεὺς Ἀλεξάνδρου καὶ καθηγητὴς καλούμενος. Strabo, p. 674, says of one of the Stoic philosophers at Tarsus, καίσαρος καθηγήσατο καὶ τιμῆς ἔτυχε μεγάλης. In the N.T. the word does not occur again. It is discarded as a title. In Soph. Greek Lex. it is said to be used for an abbot or prior of a monastery in a Synaxarion (see note ch. Matthew 18:20). καθηγητὴς is modern Greek for ‘professor.’