bulletproof

This term describes an absolute state of invulnerability. In its literal sense, it refers to physical armor or materials designed to stop projectiles, evoking a feeling of safety and impenetrable defense.

When used figuratively, it describes a plan, argument, or system that has been scrutinized and refined to the point where no flaws remain. It suggests a level of perfection that renders the subject immune to failure or external attack, often used in high-stakes professional or legal environments.