ἀποκος

From LSJ

ἔγνω δὲ φώρ τε φῶρα καὶ λύκος λύκον → the thief knows the thief and the wolf knows the wolf, and thief knows thief and wolf his fellow wolf, set a thief to catch a thief

Source

Spanish (DGE)

-ον sin pelo χιτών An.Ox.2.238.15.