The name given to a character on the DreamSMP, known as "Wilbur" or "Revivebur" after being revived by Dream.
He has been since renamed to "Dilfbur" as a joke by multiple fans.
Person 1: "Hey! Did you hear that Wilbur got revived on the DreamSMP?"
Person 2: "Oh, yeah! You mean Dilfbur?"
Person 1: "...What?"