καλοδιδάσκαλος
From LSJ
ποταμῷ γὰρ οὐκ ἔστιν ἐμβῆναι δὶς τῷ αὐτῷ → it is impossible to step twice in the same river, you cannot step twice into the same rivers
English (LSJ)
ὁ,
A teacher of virtue, Ep.Tit.2.3.
German (Pape)
[Seite 1312] ὁ, ein guter Lehrer, N. T.
Greek (Liddell-Scott)
κᾰλοδιδάσκαλος: ὁ, διδάσκαλος ἀρετῆς, Ἐπιστ. π. Τίτον β΄, 3.