The broad definition of
regicide (
Latin regis "of king" +
cida "killer" or
cidium "killing") is the deliberate killing of a
monarch, or the person responsible for the killing of a person of royalty. In a narrower sense, in the
British tradition, it refers to the
judicial execution of a king after a
trial. More broadly, it can also refer to the killing of an
emperor or any other reigning sovereign.