Definition of "tentorium"

tentorium

noun
plural tentoria or tentoriums
1. The framework of internal supports (a false endoskeleton) within an arthropod head, formed by ingrowths of the exoskeleton called apophyses.
  Quotations
  In the female of Culex the tentoria arise in front of the border of the occipital foramen and ascend at an angle of twenty-five degrees with the floor of the head.
  1906, Milett T. Thompson, Alimentary Canal of the Mosquito: (Anopheles Punctipennis)
2. (anatomy) The tentorium cerebelli, an extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes.
  Quotations
  Four dogs with intact tentoriums survived 6 weeks and 8 with sectioned tentoriums survived the same period of time.
  1961, Progress in Neurology and Psychiatry, page 345