I. ˈ ̷ ̷| ̷ ̷ adjective
Etymology: fire (I) + proof
: proof against fire : relatively noncombustible: as
a. of a building : having all parts that carry weights or resist stresses and also all exterior and interior walls and stairways made of noncombustible materials and having all structural members that are made of steel and iron, which are injuriously affected by heat, protected effectively by other materials not so affected — compare fire-resistive , fire-retardant , flameproof
b. of paper : so treated that it will char but not burn on exposure to a flame
• fire·proof·ness noun -es
II. transitive verb
: to make fireproof