Wiktionary
n. A crime committed against oneself, in particular an early twentieth-century euphemism for suicide
Wikipedia
Felo de se, Latin for "felon of himself", is an archaic legal term meaning suicide. Early English common law considered suicide a crime and a person found guilty of it, even though dead, was subject to punishments including forfeiture of property to the monarch and being given a shameful burial. Beginning in the seventeenth century law and custom gradually changed to consider a person who committed suicide to be temporarily insane at the time and conviction and punishment were gradually phased out. The term and punishments could also apply to a person killed while committing a felony.
Usage examples of "felo de se".
Before the Fact of Felo de Se and for Aiding and Abetting Felo de Se.
A person who found himself in an inferno would do anything, rape, extortion, murder, felo de se, whatever it took to get out .
Parlabane at the time of his unhappy death -- felo de se, and which of us dares point the finger -- is not our business here.