blinder

Literally to armor-plate a vehicle, but very common today in the familiar figurative senses: être blindé can mean to be emotionally hardened/jaded, to be well-prepared or safe from risk, or (older slang) to be rich.

• L'armée blinde ses véhicules avant l'opération. — The army armor-plates its vehicles before the operation.
• Après ce métier, je suis blindé, plus rien ne me choque. — After that job, I'm hardened — nothing shocks me anymore.
• On est blindés pour l'examen, on a tout révisé. — We're all set for the exam, we've reviewed everything.

The figurative être blindé is far more common in everyday speech than the literal armor-plating sense — don't assume a learner hears it about tanks; it's usually about being emotionally tough or well-prepared.

• expression "Être blindé" — Widely used French slang expression meaning to be hardened/jaded, well-protected from mishap, or (in an older sense) rich — listed in French slang dictionaries and the Académie française's entry for blindé.