Complex sentence: The word barbecue, when used as a noun, can refer to the cooking method, the meat cooked in this way, or to the cooking apparatus itself (the "barbecue grill" or simply "barbecue").
Split into simpler sentences: The word barbecue, when used as a noun can refer to the cooking method. The meat cooked in this way, or to the cooking apparatus itself (the "barbecue grill" or simply "barbecue").