Synonyms to nonbreakable

infrangible, chip-proof, coherent, cohesive, firm, firm as Gibraltar, fractureproof, impartible, indiscerptible, indissoluble, indissolvable, indivisible, infusible, inseparable, insoluble, made of iron, rigid, shatterproof, solid, sound, stable, staunch, stout, sturdy, unbreakable, undividable, unified, unshatterable, airtight, ballproof, bombproof, bulletproof, burglarproof, corrosionproof, dampproof, fire-resisting, fireproof, flameproof, foolproof, hermetic, holeproof, impervious to, leakproof, noiseproof, proof, proof against, punctureproof, resistant, rustproof, shellproof, soundproof, tight, watertight, weatherproof