ejercitar
From LSJ
πολλῶν ὁ καιρὸς γίγνεται διδάσκαλος → the critical moment will turn out to be the teacher of many things
Spanish > Greek
ἐκπονέω, ἐνασκέω, ἐγγυμνάζω, ἀπογυμνάζω, διαπονέω, διαγυμνάζω, διαμελετάω, ἀσκέω, γυμνάζω, ἐμμελετάω, ἐξασκέω