ὀρροπύγιον
From LSJ
μηδενί δίκην δικάσῃς πρίν ἀμφοῖν μῦθον ἀκούσῃς → do not give your judgement on anything until you have heard a speech on both sides
English (LSJ)
[ῡ], Ion. ὀρσοπύγιον GDI5702.35 (Samos, iv B. C.), τό: (ὄρρος):—
A rump of birds, in which the tail-feathers are set, Arist. HA504a32,618b33, al. (with vv. ll. οὐροπ-, ὀροπ-, cf. τοὐροπ- in Phld. Rh.2.189 S., but ὀρροπ- is certain in IG22.1498.27 (Athens, iv B. C.)); of the sepia, Arist.HA525a12 : generally, tail, rump of any animal, Ar.V.1075, Nu.162.
