Mud

A pair of muddy boots
Gamo mud volcano in Tokamachi, Japan

Mud is loam, silt or clay mixed with water. It is usually formed after rainfall or near water sources. Ancient mud deposits hardened over geological time to form sedimentary rock such as shale or mudstone (generally called lutites). When geological deposits of mud are formed in estuaries, the resultant layers are termed bay muds. Mud has also been used for centuries as a construction resource for mostly houses and also used as a binder.