ὀπίσσωτρον

From LSJ

πολλῶν ὁ καιρὸς γίγνεται διδάσκαλος → the critical moment will turn out to be the teacher of many things

Source

Greek (Liddell-Scott)

ὀπίσσωτρον: «ἡ ἁψίς τοῦ τροχοῦ» Ἡσύχ., ἔνθα διορθωτ. ἐπισσωτρον.