tyrannoctŏnus, i, m., = τυραννοκτόνος,
the killer of a tyrant : nostri tyrannoctoni, Cic. Att. 14, 15, 2; 16, 15, 3.
tyrannoctonus ī, m , τυραννοκτόνος, a tyrant killer, tyrannicide, regicide. ...
An Elementary Latin Dictionary