vulgar slang An outhouse, an enclosed toilet that is located outdoors, separate from a house or other building. Used especially in the phrase "built like a brick shithouse," meaning very large and muscular or very buxom and curvaceous. I hate staying at my grandpa's old cabin, because we all have to share the stinky shithouse outside when we're there. Mary's new boyfriend is build like a brick shithouse! I certainly wouldn't want to pick a fight with him.