alveolation, alveolus, antrum, armpit, basin, boll, bowl, burr, capsule, cavity, cod, concave, concavity, crater, crypt, cup, depression, dip, fold, funnel chest, hole, hollow, hollow shell, hull, husk, lacuna, legume, legumen, pease cod, pericarp, pit, pocket, pod, punch bowl, scoop, seed pod, seed vessel, seedbox, seedcase, shell, silique, sink, sinus, socket, trough, vug