adjective. Impenetrable by bullets.

adjective. Impervious to assault, damage, or failure; guaranteed.

transitive verb. To make impenetrable by bullets.

adjective. Capable of withstanding a direct shot by a bullet fired from a gun.

adjective. reliable, infallible, sturdy or error-tolerant.

adjective. Unbreakable, very tough.

verb. To make proof against bullets.

verb. to make resistant to failure.

"Athletes arrived at the opening ceremony in bulletproof vans."

infallible  sense  

bulletproofed  bulletproofing  bulletproofs