молчаливый

From LSJ

ξένῳ δὲ σιγᾶν κρεῖττον ἢ κεκραγέναι → it's better for a stranger to keep silence than to shout (Menander)

Source

Russian > Greek

ἀκραγής, σιωπηλός, ἀκέων, σιγαλός, σιγηλός, ἥσυχος