what does 'lain' mean in 'cut out of the living rock broad and lain' from The Hobbit?
Some context: The hobbit and the dwarfs are inside the Lonely mountain and this is how Tolkien describes the stairs made by the dwarfs:
They climbed long stairs, and turned and went down wide echoing ways, and turned again and climbed yet more stairs, and yet more stairs again. These were smooth, cut out of the living rock broad and lain;