thecae

/TH EH1 K EY0/
noun
  1. 1

    Any external case or sheath.

  2. 2

    The pollen-producing organ usually found in pairs and forming an anther.

  3. 3

    The twin layers of cells surrounding the basal lamina of an ovarian follicle.

  4. 4

    The membrane complex enveloping the cells of certain plankton including diatoms and dinoflagellates.

  5. 5

    The calcareous wall of a corallite, the exoskeleton of a coral polyp.

  6. 6

    A case for the corporal cloth used in the Eucharist.

Source: https://en.wiktionary.org/wiki/theca, https://en.wiktionary.org/wiki/thecae