flameproof I. \ˈ ̷ ̷| ̷ ̷\adjective 1.: resistant to the action of flame : not burning on contact with flame; especially: not tending to propagate fire if ignited 2.: safeguarded against causing destructive explosion (as by generating sparks) — used especially of machinery in mines, oil refineries, cereal mills II. transitive verb : to make flameproof