CYST

vesicle, cyst

(noun) a small anatomically normal sac or bladderlike structure (especially one containing fluid)

cyst

(noun) a closed sac that develops abnormally in some body structure

Source: WordNet® 3.1

Etymology

Noun

cyst (plural cysts)

A pouch or sac without opening, usually membranous and containing morbid matter, which develops in one of the natural cavities or in the substance of an organ.

(medicine) Of or pertaining to the urinary bladder or gall bladder (in compounds).

Source: Wiktionary

Cyst (sst), n. Etym: [Gr. Cyme.]

1. (Med.) (a) A pouch or sac without opening, usually membranous and containing morbid matter, which is accidentally developed in one of the natural cavaties or in the substance of an organ. (b) In old authors, the urinary bladder, or the gall bladder. [Written also cystis.]

2. (Bot.)

Definition: One of the bladders or air vessels of certain algæ, as of the great kelp of the Pacific, and common rockweeds (Fuci) of our shores. D. C. Eaton.

3. (Zoöl.) (a) A small capsule or sac of the kind in which many immature entozoans exit in the tissues of living animals; also, a similar form in Rotifera, etc. (b) A form assumed by Protozoa inwhich they become saclike and quiescent. It generally precedes the production of germs. See Encystment.

Source: Webster’s Unabridged Dictionary 1913 Edition