Cibber (Symbol)
In the revised version with the additional fourth book, Lewis Theobald is replaced as the King of Dulness by a figure named Cibber who is based on the then-poet laureate Colley Cibber. Pope had originally chosen Theobald as King of Dulness primarily for reasons of revenge; Theobald had criticized Pope’s edition of Shakespeare. With the deposition of Tibbald and the coronation of Cibber, the symbolism of the King of Dulness is enhanced. Cibber, a dull poet who many in Pope's time nevertheless honored, comes to symbolize in a much subtler way the concept of the “dull poet” whose verse never attains the height of artistry, thus revealing the de-evolution of the status of the position of poet laureate.
The Harlot (Symbol)
The introduction of the character of the Harlot in the fourth book is part of the expansion of what came to be called The New Dunciad into a far more allegorical work than what had existed in the original version. In those three books, Pope could fairly be accused of taking down names of his personal enemies and applying them to his kingdom of dunces, but the Harlot is a representative of the move away from purely literary targets. The Harlot is the symbolic incarnation of Italian opera who has come to announce that dullness and the commodification of artistic endeavors have infected music as well as writing.
Guild Hall (Symbol)
Guildhall was literally London’s City Hall: the hub of government where sat the city's leaders including the Lord Mayor. At the same time, Guildhall was also the seat of British trade and it is precisely this nexus between government and economics that is the locus of Pope’s satiric outrage. Government and commerce working in tandem become, from his perspective, the engine that is driving the lowering of standards and the creation of arts by and for dullards. And so Guildhall becomes the symbolic center of this lowering of quality by becoming the Guild Hall of the goddess Dulness.
The Goddess Dulness (Allegory and Symbol)
The central governing symbol in The Dunciad, and the one whose actions constitute the poem's overarching allegory, is the goddess Dulness. She represents everything that Pope believes has gone wrong with the culture of England. Pope even makes this allegory and symbolism explicit at times. For example, in an annotation to the 1743 version of the extended, four-volume Dunciad, Pope clarifies the meaning of the goddess' character. Against apparent claims that Dulness was a goddess of mere stupidity, he clarifies that she is, in fact, to be respected as representing a far more sinister aspect that includes, “Slowness of Apprehension, Shortness of Sight, or imperfect Sense of things.”
Smithfield
Smithfield is situated early on—right from the opening lines of the work—as a location at least as important symbolically as the goddess of Dulness. The choice of Smithfield as symbol indicates Pope’s own snobbery as well as illustrating his vision of a world of dunces. In the Dunciad's opening invocation, Pope calls on the goddess to lead “The Smithfield Muses to the Ear of Kings.” As a lower-class section of London home to entertainment that appealed to the most uneducated tastes, no other neighborhood in England could have served as a more powerful symbol of dull-witted readers of dull-witted literature. The idea of bringing this dull-witted entertainment to "the Ear of Kings" completes the allegorical journey of making all of England complicit in the corruption of aesthetic tastes.