κρεῖττον σιωπᾶν ἐστιν ἢ λαλεῖν μάτην → it's better to keep silence than to speak without reason (Menander)
[Seite 1241] ή, όν, argwöhnend, vermutend; adv., ὑποψιαστικῶς διακεῖσθαι πρός τι Schol. Ar. Vesp. 647; Zenob. 6, 2.
