The term "crucible" is incredibly important to Miller's work. It helps to establish a basic narrative for its major characters.
A "crucible" can be "a situation of severe trial, or in which different elements interact, leading to the creation of something new." Major characters in the drama experience this very predicament. Proctor's "crucible" involves an interaction between his desire not to get involved and the need to take action. Elizabeth's severe trial involves her commitment to telling the truth and her feelings about her husband. Hale must experience what happens when his faith in the system meets with his faith in what he knows is right. These characters experience the essence of the "severe trial" put forth in The Crucible. Such tests define their characterizations.
Another meaning of "crucible" is a container that is subjected to very high temperatures. The legal and political structure of Salem represents this particular idea of a "crucible." The witch trials put a great deal of intense pressure on the town. Men like Parris, Hathorne, and Danforth believe that they will withstand this searing level of intensity. However, Miller notes that as a result of this experience “the power of theocracy in Massachusetts was broken.” Abigail is placed inside this crucible. She is forced to commit and live with deception. It is interesting that she does not remain in Salem, having run away to Boston and become a prostitute. Abigail is not able to withstand the "high temperature" of the crucible that she initiated.
The title of Miller's drama is incredibly relevant in both understandings of the term "crucible."