Boudin, black pudding in English, is essentially pig's guts filled with blood and other ingredients, such as onions, spinach, etc. (French pronunciation: [budɛ̃]) The added ingredients vary in French, Luxembourgish, Belgian, Swiss, Québec, Acadian, Aostan, Louisiana Creole, and Cajun cuisine. Etymology. The Anglo-Norman word boudin meant 'sausage', 'blood sausage', or 'entrails' in general. Its origin is unclear. It has been traced both to Romance and to Germanic roots, but there is not good evidence for either (cf. boudin).
https://en.wikipedia.org/wiki/Boudin