barbecue sauce UK /ˈbɑːbɪkjuː sɔːs/US /ˈbɑːɹbəkjuː sɑːs/ noun1 •A fruity, tangy, usually brown sauce, typically consisting of a vinegar or tomato base with spices and sweeteners, used as a basting sauce, marinade, or condiment, especially for barbecued meat. formsbarbecue sauces