βουρδῶνιν
From LSJ
ἀμήχανον δὲ παντὸς ἀνδρὸς ἐκμαθεῖν ψυχήν τε καὶ φρόνημα καὶ γνώμην, πρὶν ἂν ἀρχαῖς τε καὶ νόμοισιν ἐντριβὴς φανῇ → hard it is to learn the mind of any mortal or the heart, 'till he be tried in chief authority | it is impossible to know fully any man's character, will, or judgment, until he has been proved by the test of rule and law-giving
Spanish (DGE)
-ου, τό
mula ἵππους καὶ τὸ β[ουρ] δῶ[νι] ν PHarris 155.4 (biz.) en BL 3.82.