Consider the characters Pearl, Dimmesdale, and Chillingworth. How are their names symbolic?
The narrator actually does offer a some information concerning Hester's choice to name her daughter Pearl. He says that Hester choosing the moniker,
not as a name expressive of [Pearl's] aspect, which had nothing of the calm, white unimpassioned lustre that would be indicated by the comparison. But she named the infant "Pearl," as being of great price—purchased with all she had—her mother's only treasure.
In other words, Hester chooses the name because of the high cost of a pearl because her daughter had cost her everything else she had: she went to prison, and she lost her good reputation as well as the chance of ever being able to be with Pearl's father. Also, she treasures Pearl, and so it makes sense to name her after something of great value.
In addition, there is more symbolism to be found in this little girl's name. Pearls are white, and white is often associated with purity and innocence—something with which Hester will not be associated at this point as a result of her extramarital affair—but little Pearl may yet benefit if her name reminds others that though her mother is tainted by her sin, Pearl is innocent of it. Further, a pearl begins as a piece of sand—something neither beautiful nor special—and then, as a result of the work of the oyster into which the grain of sand was taken, it becomes something exceptional and gorgeous and valuable. Perhaps, then, we might look at Pearl's origin of Hester's illegal and unethical affair as her inauspicious beginning (the grain of sand), so that we can look with hope toward her development into something exceptional and beautiful (the pearl which develops from the sand).
There's also the broader symbolism having to do with nature, and pearls are found in nature. Unlike many female Puritan names that focus on virtue (Prudence, Constance, Charity, and so forth), Pearl's name is derived from something in nature rather than any virtue championed by society. In this way, then, Hester differentiates her child from her community and draws on the beauty and goodwill of nature—something the narrator discusses early on in his description of the rose bush outside the prison and which becomes apparent when Hester removes her cap and letter in the woods, later on.
Pearl's name is symbolic in that pearls have a luster or radiance about them, just as Hester's daughter does. Hester dresses her in fabrics that reflect the radiance of her soul. Pearl was the product of sin, yet she does not suffer any physical characteristics from the turmoil that resulted in her birth. Pearl is rare as she does not accept the poor treatment she receives from the townsfolk quietly, and her unique (and temperamental) personality is fitting for one named Pearl.
The name Dimmesdale sounds as if one is not bright. And it can be argued that some of his choices were not the smartest he could have made. Dimmesdale allows Hester to bear the brunt of the humiliation for their sin, although he is being eaten away by his secret guilt. Dimmesdale is also to Chillingworth's motives, as well. He does not seem to grasp that the constant prying into his life is not of any medical necessity. Chillingworth was supposed to be helping him medically, not trying to psychologically manipulate him. Dimmesdale does not seem to know what Chillingworth is up to.
Chillingworth's name reflects his cold personality, as well as the frosty reaction to his physical appearance he receives. Coupled with his name, his appearance adds to the perception of his true evil nature, as the novel progresses, he seems to be getting darker.