Encrustation is a process of covering a surface with a hard layer, usually made of a material such as rock, ice, or minerals. The two crossword solutions for this term are CAKING (6 letters) and SCAB (4 letters). Caking is the process of forming a hard crust on the surface of something, usually by baking or drying. SCAB is a hard, dry crust that forms over a wound or sore to protect it from infection. Both processes involve the formation of a hard layer on a surface, which is the definition of encrustation.