The term FIRE PROOF is composed of five words: ASH (3 letters), ASHES (5 letters), SOOT (4 letters), EMBERS (6 letters), and FIREPROOF (9 letters). ASH is a powdery residue left after the combustion of organic material, such as wood. ASHES are the remains of something that has been burned. SOOT is a black or dark brown substance made up of tiny particles of carbon that is produced when something is burned. EMBERS are glowing, hot pieces of coal or wood that remain after a fire has gone out. FIREPROOF is an adjective that describes something that is resistant to fire or cannot be burned.