Cists

Part of speech: noun

Definitions

1. A sac-like structure in biological contexts, often containing fluid or tissue
2. a small closed cavity found within an organism, holding developed or developing tissues
3. a protective enclosure for certain cell types or spores in various life forms

Etymology: "Cists" is the plural of "cist," and the noun has two separate routes into English. One runs from the Latin "cista," meaning chest or casket, which itself came from the Ancient Greek "kistē," meaning basket or box. That same Latin root gave English the word "chest," so the two are doublets, sharing a origin but reaching English by different paths. The other route came through Welsh. Welsh "cist" also means chest, and it was borrowed into English in the archaeological sense of a stone-lined burial chamber, the kind that appears in the term "kistvaen," a Welsh word for a box-shaped grave made of stone slabs. Biology later borrowed the word for a closed cavity inside an organism that encloses developing or developed tissue, so "cists" in that sense carries a box-and-container meaning across fields that otherwise have little in common.