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