The term 'flood residue' refers to the material left behind after a flood. This material can include MUCK (4 letters) and MUD (3 letters). MUCK is a type of soil that is made up of organic matter, such as decaying plants and animals, and is usually found in wetlands. MUD is a mixture of water and soil particles, which can be created by floods or other natural disasters. Both MUCK and MUD are common components of flood residue.