What does the word "festers" mean? What does it communicate about the Breedlove household?

Feester: To worsen, especially due to lack of attention. The prejudice and treatment that Pecola receives because of her skin color is called "colorism," a sister type of discrimination that has only recently been studied and researched. In colorism, those with lighter skin are given preferential treatment while those with darker skin are often treated harshly.