Meaning

noun a closed sac that develops abnormally in some body structure

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

originEtymology tree Proto-Indo-European *(s)kewH-? Proto-Indo-European *ḱewh₁-der.? Ancient Greek κύω (kúō)? Ancient Greek κύστις (kústis)der. Late Latin cystisder. English cyst From Late Latin cystis, from Ancient Greek κύστις (kústis, “anatomical sac”).

Etymology from Wiktionary, CC BY-SA 3.0