Becoming solid is a process that involves changing from a liquid or gas state to a solid state. CLOT, SET, SOLIDIFY, HARDEN, and GEL are all words that describe this process. CLOT is a four letter word that means to form a mass of coagulated material. SET is a three letter word that means to make firm or stable. SOLIDIFY is an eight letter word that means to make or become solid. HARDEN is a six letter word that means to make or become hard or harder. GEL is a three letter word that means to form into a jelly-like mass.