Synonyms and related words :
airtight, ballproof, bombproof, bulletproof, burglarproof, chip-proof, corrosionproof, dampproof, fire-resisting, fireproof, flameproof, foolproof, fractureproof, hermetic, holeproof, impervious to, infrangible, leakproof, noiseproof, nonbreakable, proof, proof against, punctureproof, resistant, rustproof, shellproof, soundproof, tight, unbreakable, unshatterable, watertight, weatherproof