tentorium

Etymology
Early 19th century: from, literally ‘tent’.

Noun

 * 1) The framework of internal supports (a false endoskeleton) within an arthropod head, formed by ingrowths of the exoskeleton called apophyses.
 * 2)  The tentorium cerebelli, an extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes.
 * 1)  The tentorium cerebelli, an extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes.

Etymology
From.

Noun

 * 1) tent