Noncombustible refers to materials that do not burn or ignite when exposed to extreme heat or flames. There are several synonyms for this term, which include incombustible, fireproof, flameproof, and fire-resistant. Incombustible means incapable of burning or being set on fire. Fireproof and flameproof both mean able to resist or withstand fire or intense heat without damage. Fire-resistant means able to resist or withstand fire without igniting or burning. These synonyms are commonly used in construction, manufacturing, and engineering industries to describe materials that meet stringent safety standards and regulations. It is important to understand the different synonyms related to noncombustible materials to ensure safety and compliance in various settings.