Introitus, facial canal
In anatomy, an introitus is an entrance, one that goes into a canal or hollow organ.
The introitus of the facial canal is the entrance to the facial canal, a passage in the temporal bone of the skull through which the facial nerve (the 7th cranial nerve) travels.
The Latin word 'introitus' comes from 'intro', into, within + 'ire', to go = to go into.
The vagina also has an introitus, an entrance.