fratricide
From LSJ
ἐάν μή διδάξητε περί ἀρετὴς τούς τό ἀργύριον κλέψαντας, οὐ ταξόμεθα οἱ ὁπλῖται → if you don't teach those who have stolen money a lesson on moral virtue, we, the hoplites, will not line up
English > Greek (Woodhouse)
substantive
murder of a brother: use P. and V. ἀδελφοῦ φόνος, ὁ.
murderer of a brother: P. and V. ἀδελφοῦ αὐθέντης, ὁ; see murderer.