TRASH. The Cunninghams are a step up on the social ladder of Maycomb according to Jem Finch (in descending order, there are "the ordinary kind like us," "the Cunninghams," "the Ewells," and "the Negroes"), but Alexandra believes differently. To her, there is little to separate the Ewells and Cunninghams. Scout cannot socialize with Walter Jr., Alexandra asserts, "Because--he--is--trash!" The rest of the Finches seem to agree that the Cunninghams are not in the same class as the Ewells, "the disgrace of Maycomb County for three generations."
REDNECK HILLBILLIES. The word "redneck" is never used in the novel, nor are there any real hills in southern Alabama, but the Cunninghams seem to fit this description otherwise. The family is closely related--Atticus tells of the Cunninghams who are "double first cousins"--they don't attend church, they hang out and gamble at the Dew Drop Inn, and they "experimented with stumphole whiskey." They farm and pay their bills with bartered goods, and they get drunk before they carry out their planned lynch party.
CUNNING. Author Harper Lee almost certainly chose the name of Cunningham deliberately, since the family does show a bit of cunning during the story. Walter Sr. manages to postpone his "entailment" problems by smartly hiring Atticus to defend him in court. The family outwits Heck Tate on the night of their planned lynching of Tom Robinson by sending the sheriff on a "snipe hunt." Even Atticus is surprised by the turn of events, telling Walter that "that changes things, doesn't it?"
The cunninghams are stereotyped as poor people who don't take anything that they can't pay back (which is pretty much anything), and they are low on the social class order, so people don't necessarily treat them with respect.