- Hypnocyst Hyp"no*cyst, n. [Gr. ? sleep + E. cyst.] (Biol.) A cyst in which some unicellular organisms temporarily inclose themselves, from which they emerge unchanged, after a period of drought or deficiency of food. In some instances, a process of spore formation seems to occur within such cysts. [1913 Webster]
The Collaborative International Dictionary of English. 2000.