ἠκηκόειν

From LSJ

καὶ τὸ σιγᾶν πολλάκις ἐστὶ σοφώτατον ἀνθρώπῳ νοῆσαι → and silence is often the wisest thing for a man to heed, and often is man's best wisdom to be silent, and often keeping silent is the wisest thing for a man to heed

Source

French (Bailly abrégé)

v. ἀκούω.

Greek Monotonic

ἠκηκόειν: υπερσ. του ἀκούω.