The Dizionario Italiano of Sabatini-Coletti gives both "ossobuco" and "osso buco" as spellings. They have it derived from Milanese dialect "ós büs", meaning hollow bone, and date it from around 1869. It is the name of the cut of the ox femur, with marrow and the surrounding meat, as well as of the dish prepared from it. Jan Ivarsson jan.ivarsson at transedit.st