n. In anatomy, a bladder; a large vesicle.n. In pathology, a bladder-like bag or vesicle in animal bodies which includes morbid matter.n. In zoology, a hydatid; a cystic worm, or encysted state of a tapeworm.n. In cryptogamic botany, a cell or cavity, usually inclosing other cells or reproductive bodies, as an envelop inclosing a group of diatoms or desmids, or a cell containing an antherozoid; in certain algæ, a sporecase. See coniocyst.n. Sometimes, improperly, cist.n. The resistant coating formed by the parent organism previous to sporulation and inclosing the spores, in Sporozoa.n. In Sporozoa, the common envelop surrounding the two associated gametocytes.n. The resistant covering secreted by many Infusoria previous to going into a resting-stage, or before fission, or for the purpose of resisting draught or other unfavorable conditions of environment.