What is Petit, Treason?

Legal Definition
English law. The killing of a master by his servant; a husband by his wife; a superior by a secular or religious man. In the United States this is like any other murder. See High, Treason; Treason.
-- Bouviers Law Dictionary
Legal Definition
In English law. The crime committed by a wife in killing her husband, or a servant his lord or master, or an ecclesiastic his lord or ordinary. 4 Bl. Comm. 75.
-- Black's Law Dictionary
Legal Definition
The killing of a master by a servant; of a husband by a wife; of a superior by an ecclesiastic.
-- Ballentine's Law Dictionary