An implicit or indirect reference to another work of literature, a historical or mythical person or event is called _____.

Allusion:
An implicit or indirect reference to another work of literature, a historical or mythical person or event.
Example:
Not half so fixed the Trojan could remain,
While Anna begged and Dido raged in vain.
(Pope: The Rape of the Lock)
- Here is an allusion to the dilemma of Aeneas, the hero of Virgil's Aeneid.
Source: An ABC of English Literature - Dr M Mofizar Rahman