Answer:
An allusion is a literary device that provides greater context to the work at hand by referencing a previous work of art, a person, a place, an event, or a situation—usually of some social, political, or historical significance.
For example: You're acting like such a Scrooge! Alluding to Dickens's A Christmas Carol, this line means that the person is being miserly and selfish, just like the character Scrooge from the story.