What is definition of protagonist?

The definition of protagonist is the character around which the plot of the story centers. Although many misinterpret protagonist to mean the hero or “good guy,” this is not always the case. If one examines the main conflict within a story, then one should be able to determine the protagonist by simply asking oneself: whom or what is most affected by the main conflict in the story?
In the case of William Faulkner’s famous short story, “A Rose for Emily,” the central conflict is the pressure of society and its judgment. The person who suffers at the hands of society’s unyielding judgment is, of course, Miss Emily Grierson of title fame.
Although the reader never hears from Miss Emily directly, the narrator focuses his or her story on the circumstances of Emily’s life and death, and her impact on the people of Jefferson.