Early 19th century; earliest use found in Fortescue Cuming (1762–1828). From Louisiana French casse-burgo, cazeburgot, casse-burgau from casser to break + burgau, burgo, name of a species of shellfish. The fish name probably originated in France, being transferred to the American fish: for evidence from French regional varieties and further discussion see W. A. Read Notes on 'gaspergou' in Amer. Speech 20 277–80.