A cookhouse is a kitchen where food is cooked, especially outdoors or in a simple separate building — most often at a military camp, a work camp, or an old-style camp. Soldiers line up at the cookhouse; camp meals come from the cookhouse. You will not hear this much in ordinary city life. A ship's kitchen is more often called a galley. A restaurant is not a cookhouse, even though food is cooked there. Though actually, the word is just cook + house: a house (or hut) for cooking, not a fancy kitchen and not a cooking class.