“Cleaving the spine” (rhakhizon) is a word which comes from a rather extreme cut through the back (rhakhis). Metaphorically, then, we call those who do terrible things “spine cleavers.”
εἴρηκε δὲ ῥαχίζων διὰ τὸ τὴν πρώτην καὶ μεγάλην διακοπὴν κατὰ ῥάχιν γίνεσθαι. ἐκ μεταφορᾶς καὶ τοὺς μεγάλα κακουργοῦντας ῥαχιστάς φαμεν
