Patricide is (i) the act of killing one's father, or (ii) a person who kills his or her father. The word patricide derives from the Latin word pater (father) and the Latin suffix -cida (cutter or killer). Patricide is a sub-form of parricide, which is defined as an act of killing a close relative. In many cultures and religions patricide was considered one of the worst sins. For example, according to Marcus Tullius Cicero, in the Roman Republic it was the only criminal act for which the punishment was an execution.