Wiktionary
n. A traditional sandwich from Louisiana, consisting usually of meat or seafood, and always in a French-style baguette.
Wikipedia
A po' boy (also po-boy, po boy, or poor boy) is a traditional sandwich from Louisiana. It almost always consists of meat, which is usually sloppy roast beef, or fried seafood which includes shrimp, crawfish, oysters and crab. The meat is served on baguette-like New Orleans French bread that is known for its crisp crust and fluffy center or in a basket.
Usage examples of "po' boy".
That means beignets and crayfish bisque and jambalaya, it means shrimp remoulade, pecan pie, and red beans with rice, it means elegant pompano au papillote, funky file z'herbes, and raw oysters by the dozen, it means grillades for breakfast, a po' boy with chowchow at bedtime, and tubs of gumbo in between.