unassailable unshakable watertight bulletproof
unassailable%5:00:00:incontestable:00 unshakable%5:00:00:incontestable:00 watertight%5:00:00:incontestable:00 bulletproof%5:00:00:incontestable:00
neomajen
without flaws or loopholes
an ironclad contract a watertight alibi a bulletproof argument