cist / cyst / sissed [sɪst]
cist – n. – 1. Archeology a coffin or burial chamber made; 2. a wicker receptacle for carrying sacred utensils in ancient Rome
cyst – n. – 1. Med. an abnormal sac containing fluid, pus, etc.; 2. Biol. a hollow organ or bladder, etc., in an animal or plant containing a liquid secretion; 3. a cell or cavity enclosing reproductive bodies, an embryo, parasite, microorganisms, etc.
sissed – v. p. tense of siss – to make a hissing sound