Allusion: 
A direct or indirect reference to something which is commonly known, such as an event, book, myth, place, or work of art. Allusions can be historical, literary, religious, or mythical. 

Example:
"Pearl of great price" -Scarlet Letter 


Explanation: 
Pearl is the name of Hester's daughter. Hawthorne uses this as her name because it is an allusion to the gospel of Matthew: "Again, the kingdom of heaven is like unto a merchant man, seeking goodly pearls: Who, when he had found one pearl of great price, went and sold all that he had, and bought it." This explains it all, Hawthorne uses this allusion in his novel to refer to pearl as the jewel that Hester won, but through a great price (her scarlet letter), just like in the gospel of Matthew. Hawthorne uses biblical allusions in this novel because it is relevant for that time period.