Water soaked soil; soft wet earth WordNet 3.0 & Open English WordNet

Mud is soil, loam, silt or clay mixed with water. Wikipedia

Mixture of water and any combination of soil, silt, and clay Wikidata

A mixture of clay and/or silt with water to form a plastic mass with a particle size preponderantly below 0.06 mm diameter. It is deposited in low-energy environments in lakes, estuaries and lagoons. It may also be deposited in deep-sea environments. OmegaWiki