marsh swamp mire bog fen

1. marsh: [C, U] 湿地；沼泽；草本沼泽
   An area of low land that is always soft and wet because there is nowhere for the water to flow away to.
2. swamp: [C, U] 沼泽（地）
   An area of ground that is very wet or covered with water and in which plants, trees, etc. are growing
   同义词：marsh
3. mire:
   n.泥潭;泥沼
   v.(使)陷于泥泞;(使)陷入困境
   An area of deep mud.
   同义词：bog
4. bog
   n.沼泽(地区);厕所;浴室
   v.（使）陷于泥沼;（使）动弹不得
   (an area of) wet soft ground, formed of decaying plants
5. fen
   n. (尤指英格兰东部) 低位沼泽，沼泽;
   An area of low flat wet land, especially in the east of England