ten.ˈtōrēəm noun
( plural tento·ria -rēə)
Etymology: New Latin, from Latin, tent, from tentus (past participle of tendere to stretch) + -orium
1. or tentorium ce·re·bel·li -ˌserəˈbeˌlī
[ tentorium cerebelli, from New Latin, literally, tentorium of the cerebellum]
: an arched fold of dura mater covering the upper surface of the cerebellum, supporting the occipital lobes of the cerebrum, having its posterior and lateral border attached to the skull and its anterior border free, and in some forms (as the cat) being completely ossified
2. : the internal chitinous skeleton of an insect's head formed usually of two or three paired apodemes arising from the chitinous head capsule