"hot dog," 1894, American English, from German Frankfurter "of Frankfurt," because a smoked-beef-and-pork sausage somewhat like a U.S. hot dog was originally made in Germany, where it was associated with the city of Frankfurt am Main (literally "ford of the Franks on the River Main"). Attested from 1877 as Frankfort sausage.
highly seasoned sausage, traditionally of mixed pork and beef. Frankfurters are named for Frankfurt am Main, Ger., the city of their origin, where they were sold and eaten at beer gardens.