kansiluukku
kulkuluukku
A means of passing through a wall or floor, having a hatch (especially on a ship); a doorway with a hatch rather than a door.
{{quote-book|en|year=1924|author=Herman Melville|title=Billy Budd|location=London|publisher=Constable & Co.|chapter=22|url=http://gutenberg.net.au/ebooks06/0608511h.html