This compound noun designates a person who kills other humans. Jesus uses it of the devil, calling him 'a murderer from the beginning' (John 8:44), linking Satan's deadly nature to his fundamental character. John's first epistle employs it twice to describe the spiritual state of those who hate their brothers—such hatred constitutes spiritual murder, excluding one from eternal life (1 John 3:15). The word combines 'human' (ἄνθρωπος) and 'killer' (κτόνος), making the target of the violence explicit.