βαρβαρικόν

From LSJ

τὸ δὲ ποιεῖν ἄνευ νοῦ ἃ δοκεῖ καὶ σὺ ὁμολογεῖς κακὸν εἶναι: ἢ οὔ → but doing what one thinks fit without intelligence is—as you yourself admit, do you not?—an evil

Source

Russian (Dvoretsky)

βαρβᾰρικόν: τό
1 мир варваров, т. е. не греки Thuc., преимущ. персы Xen.;
2 варварский способ: ἐς τὸ β. Luc. варварски, грубо.