The word is used for pork, veal lamb, beef or even rabbit, meaning a choice rib cut from the rear or center of the animal—Italians will cut that part either as chops or as a roast.
For beef, a chop here would be the equivalent of a sirloin steak; it's what they use for bistecca alla fiorentina. For veal, it is sometimes called lombattina. Pork lombo or lombata is often sliced into thin cutlets.
lombo di latte: (north Italy) pork slow-cooked in the oven in milk, scented with bay, sage and lemon