FIREPROOF
fireproof
(adjective) impervious to damage by fire
fireproof
(verb) make resistant to fire
Source: WordNet® 3.1
Etymology
Adjective
fireproof (comparative more fireproof, superlative most fireproof)
Resistant to damage from fire.
Synonyms: fire-resistant, flame-retardant, refractory
Verb
fireproof (third-person singular simple present fireproofs, present participle fireproofing, simple past and past participle fireproofed)
To make resistant to damage from fire.
Source: Wiktionary
Fire"proof`, a.
Definition: Proof against fire; incombustible.
Source: Webster’s Unabridged Dictionary 1913 Edition