The term 'thick mass' can be described by four different crossword solutions: CLUMP (5 letters), SLAB (4 letters), CLOT (4 letters), and GLOB (4 letters). CLUMP is a noun that refers to a group of things that are close together, usually in a disorganized way. SLAB is a noun that refers to a large, flat piece of material, such as stone or wood. CLOT is a noun that refers to a thick mass of something, such as blood or mud. Finally, GLOB is a noun that refers to a round mass of something, such as a drop of liquid.