Final answer:
The ghost's description in Act 1, Scene 5 of the regicide refers to William Shakespeare's play 'Hamlet', where King Hamlet's ghost reveals his murder by Claudius.
Step-by-step explanation:
The ghost's description of the regicide in Act 1, Scene 5 is a reference from the literary work Hamlet, written by William Shakespeare. The ghost of King Hamlet describes how his life was taken by his own brother Claudius, who poured poison in his ear while he was asleep in his orchard. This act of treachery led to Claudius taking over the throne of Denmark and marrying King Hamlet's widow, Queen Gertrude.