straight sinus vs tentorial sinus

straight sinus and tentorial sinus both are nouns.

Word	Noun	Adjective	Verb	Adverb
straight sinus	Yes	No	No	No
tentorial sinus	Yes	No	No	No

As nouns, straight sinus and tentorial sinus are synonyms defined as:

Other synonyms of straight sinus include sinus rectus.

straight sinus (noun)	tentorial sinus (noun)
an unpaired sinus of the dura mater	an unpaired sinus of the dura mater