The word "沼泽地" is formed by combining three characters: 沼, meaning "pool" or "marsh"; 泽, meaning "swamp" or "marsh"; and 地, meaning "land" or "ground". The first two characters together, 沼泽, specify a marshy or swampy area, and the addition of 地 clarifies it as a type of terrain, resulting in the compound meaning of "swampland" or "marshland".