مثانة

Etymology
From meaning to be doubled, to bend or curve into two equal parts, to be folded over. Alternatively from, meaning to be lowest or closest to the ground, the lowest part of a human abdomen, the space between the bellybutton and the beginning of the pubic region.

Noun

 * 1)  urinary bladder
 * 2)  a cyst
 * 3) a sac
 * 4) a pocket or pouch