1911 Encyclopædia Britannica/Ben

BEN (from Old Eng. bennan, within), in the Scottish phrase “a but and a ben,” the inner room of a house in which there is only one outer door, so that the entrance to the inner room is through the outer, the but (Old Eng. butan, without). Hence “a but and a ben” meant originally a living room and sleeping room, and so a dwelling or a cottage.