незагрязненный

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

Russian > Greek

ἀθόλωτος, καθαρός