Sororicide

Sororicide is the act of killing one's own sister. It derives from the Latin soror for sister and -cide, derived from caedere, to cut or kill.

There are a number of examples of soricide and fratricide (the killing of one's brother) in juveniles, even pre-adolescents, where sibling rivalry and resulting physical aggression can get out of hand and lead to the death of one of them, particularly if a firearm is available or if one is significantly older than the other and misjudges his/her own strength.

Compare with child murder (the killing of an unrelated child), infanticide (systematic killings of a large number of children), filicide (the killing of a child by his or her parent), and patricide and matricide (the killing of a father or mother respectively by his or her child).