(ËkÃ¦sÉËrÉÊl) n. 1. (Cookery) a covered dish of earthenware, glass, etc, in which food is cooked and served. Also called: casserole dish. 2. (Cookery) any food cooked and served in such a dish: chicken casserole. vb. (Cookery) to cook or be cooked in a casserole.