1) Allusion - noun
1. in literature, an implied or indirect reference to a person, event, or thing or to a part of another text. Allusion is distinguished from such devices as direct quote and imitation or parody. Most allusions are based on the assumption that there is a body of knowledge that is shared by the author and the reader and that therefore the reader will understand the author's referent.

Christy didn't like to spend money. She was no Scrooge, but she seldom purchased anything except the bare necessities.
In The Adventures of Huckleberry Finn, the Grangerfords and Shepardsons are an allusion to Shakespeare's Montagues and Capulets.