The term SAC can refer to several different anatomical structures. The seven letter solution, BLADDER, is an organ in the lower abdomen that stores urine. The five letter solution, POUCH, is a small BAG or container used to store items. The three letter solution, BAG, is a flexible container used to store items. The four letter solution, CYST, is a closed sac containing fluid or semisolid material. The six letter solution, AMNION, is a thin membrane that surrounds and protects a developing embryo. The three letter solution, POD, is a dry, dehiscent fruit that splits open when ripe. The five letter solution, culde, is a small sac or POUCH in the body. The five letter solution, BURSA, is a small fluid-filled sac that cushions and reduces friction between tissues. The seven letter solution, VESICLE, is a small sac filled with fluid.