Incombustible Incombustible antonyms flammable combustible inflammable burnable ignitable incendiary waterproof fiery ablaze afire aflame Full list of antonyms (27) Incombustible synonyms noncombustible fireproof nonflammable noninflammable flameproof fire-resistant non-inflammable non-combustible uninflammable non-flammable flame-retardant Full list of synonyms (32)