What does Boxing Day have to do with boxing?
1751, American English, apparently named for the pot it was cooked in: French chaudière "a pot" (12c.), from Late Latin caldaria (see caldron). The word and the practice introduced in Newfoundland by Breton fishermen, and spreading thence to New England.
CHOWDER. A favorite dish in New England, made of fish, pork, onions, and biscuit stewed together. Cider and champagne are sometimes added. Pic-nic parties to the sea-shore generally have a dish of chowder, prepared by themselves in some grove near the beach, from fish caught at the same time. [John Russell Bartlett, "Dictionary of Americanisms," 1859]The derogatory chowderhead (1819) is a corruption of cholter-head (16c.), from jolthead, of unknown origin.
in North American cuisine, hearty soup usually containing fish or shellfish, especially clams. The word chowder is a corruption of the French chaudiere ("cauldron"), and chowder may have originated among Breton fishermen who brought the custom to Newfoundland, whence it spread to Nova Scotia, New Brunswick, and New England. The standard New England-style chowder contains fish or shellfish, salt pork, onions, potatoes, and milk. Manhattan-style chowder replaces the milk with tomatoes. Eighteenth-century chowders were more varied; meat or poultry chowders were made, and wine, spices, herbs, cider, and other flavourings were often added. Pounded common crackers or ship biscuits served as thickening. In the Southern and Midwestern United States, fresh sweet corn (maize) often replaces the clams in chowder. Conch chowder is a specialty of Key West, Fla.