Crossword Genius

Dungeon with only a roof entrance (9)

Ross

I believe the answer is:

oubliette

(Another definition for oubliette that I've seen is " Trapdoor-accessed dungeon".)

I've seen this clue in The Times.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.