ἀπόφθεγξις

From LSJ

σιγᾶν ἄμεινον ἢ λαλεῖν ἃ μὴ πρέπει → it's better to keep silence than to say what's not appropriate (Menander)

Source

Spanish (DGE)

-εως, ἡ sentencia, apotegma Anon.ined.Vat.1.1.