nematocyst

Formed as nemato- +‎ cyst after the French nématocyste.

nematocyst (plural nematocysts)

1. (biology) A capsule, in certain cnidarians, containing a barbed, threadlike tube that delivers a paralyzing sting
   • 1885, R. J. Harvey Gibson, “Observations on the nematocysts of Hydra fusca”, in Proceedings of the Literary and Philosophical Society of Liverpool‎, volume 39, page 30:

     Often one sees, on surface view, a distinctly rounded vacuole, occupying a position in the cell occupied in others by a large nematocyst.

   • 1902, Arthur Willey, Zoological Results Based on Material from New Britain, New Guinea, Loyalty Islands and Elsewhere‎, page 379:

     The young nematocyst decreases in size and becomes coarsely granular, the granules arranging themselves in a spiral line close under the external membrane.

   • 2014, Anthony K. Campbell, Intracellular Calcium‎, page 350:

     Nematocyst discharge is another example of the Rubicon principle – it either fires or it does not.

• cnida
• cnidocyst
• cnidocyte