Main Entry: cavernous sinus Function: noun : either of a pair of large venous sinuses situated in a groove at the side of the body of the sphenoid bone in the cranialcavity and opening behind into the petrosal sinuses
cavernous sinusn. Either of a pair of dural sinuses on either side of the sella turcica, connected by anastomoses in front of and behind the pituitary gland.