ἐλέμπορος
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
Spanish (DGE)
-ου, ὁ mercader, comerciante de aceite, ISmyrna 245.2 (II/III d.C.).