Fratricide

Fratricide (from Latin fratricidium; from frater 'brother' and -cīdium 'killing' – the assimilated root of caedere 'to kill, cut down') is the act of killing one's own brother. It can either be done directly or via the use of either a hired or an indoctrinated intermediary (an assassin). The victim need not be the perpetrator's biological brother. In a military context, fratricide refers to a service member killing a comrade. The term is often used metaphorically to refer to civil wars.