σιγᾶν ἄμεινον ἢ λαλεῖν ἃ μὴ πρέπει → it's better to keep silence than to say what's not appropriate (Menander)
obedient: P. and V. εὐπειθής (Plato), κατήκοος (Plato), V. εὐπιθής, πείθαρχος.
obliging: P. and V. εὐχερής.
