What is "thiirane"

n. (context organic compound English) The saturated three-membered heterocycle containing two carbon atoms and one sulfur atom; ethylene sulfide

Thiirane, more commonly known as ethylene sulfide, is the cyclic chemical compound with the formula CHS. It is the smallest sulfur-containing heterocycle and the simplest episulfide. Like many organosulfur compounds, this species has a stench. Thiirane is also used to describe any derivative of the parent ethylene sulfide.