Fen and Peat bog

Fen noun - Spongy land saturated or partially covered with water.

Peat bog and fen are semantically related in marsh topic. In some cases you can use "Peat bog" instead a noun "Fen", when it comes to topics like swamp. popular alternative

Nearby Word: fens

Peat bog noun - Wet spongy ground of decomposing vegetation; has poorer drainage than a swamp; soil is unfit for cultivation but can be cut and dried and used for fuel.

Fen and peat bog are semantically related in swamp topic. You can use "Fen" instead a noun phrase "Peat bog", if it concerns topics such as marsh, wet land covered with vegetation.