οὐδάμινος
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
English (LSJ)
η, ον (proparox., cf. Hdn. Gr. 2.26), worthless, good for nothing, J.AJ17.2.4, 18.7.1, Heph.Astr.3.2, Anon. in Rh.186.16, Hsch.