ὑπερθνήσκειν

From LSJ

κρεῖττον σιωπᾶν ἐστιν ἢ λαλεῖν μάτην → it's better to keep silence than to speak without reason (Menander)

Source

Greek > English (Woodhouse Verbs Reversed)

(see also: ὑπερθνήσκω) be a martyr to, die for