In the United States, a brownstone is a city house whose front is made of a reddish-brown stone, so the whole house takes that name. You see long rows of them in New York City especially — a stoop (the steps) up to the door, and that warm brown-red face looking onto the street. People say “a brownstone” to mean the house, not a lump of rock. The stone is a kind of sandstone that looks brown-red; many of these houses went up in the 1800s and now feel old, solid, and a bit grand. Other US cities have some too, but New York is the picture in most people’s heads. Though actually, not every brown-looking house is a brownstone: the word is for this stone and this style, not for any house painted brown.