δαμαστέον
From LSJ
ξένῳ δὲ σιγᾶν κρεῖττον ἢ κεκραγέναι → it's better for a stranger to keep silence than to shout (Menander)
English (LSJ)
A one must break in, τριετῆ πῶλον Gp.16.1.11. II Adj. -τέος, α, ον, Hsch. s.v. δματέα.
Spanish (DGE)
hay que domar (πῶλον) γενόμενον δὲ τριετῆ Gp.16.1.11, cf. Hsch.s.u. δματέα.