cyst
[C] Countable
pl: cysts
The word carries a clinical, sterile feeling and is almost exclusively used in medical or biological settings. It evokes an image of a contained, isolated pocket that is distinct from the surrounding healthy tissue, often suggesting something that needs to be drained or excised to restore normalcy. In a biological sense, the term shifts from a pathology to a survival strategy. Here, it describes a protective armor that allows a microscopic organism to enter a state of suspended animation, waiting for the right conditions to awaken.
Countable when referring to individual sacs in a patient or individual dormant shells of a parasite.