bombproof

adj

1. Sufficiently strong to resist the effects of a blast from a bomb.

   “bombproof buildings”

2. (figuratively, informal)Very sturdy; as if built to resist the effects of a blast from a bomb.

   “Steve's steel-frame mountain bike is heavy and slow, but it's bombproof.”

noun

1. An air-raid shelter, a structure designed to give protection against air raids and bombs.

   “As I waded through the mud to go down into the bombproof, it struck me uneasily that our officers glanced at each other.”

   “At night, when the Federal guns slowed their fire, the men created new traverses and bombproofs.”

   “It mounted a 10-inch Columbiad and two 32-pounders on the sea face, with field guns and other 32-pounders elsewhere. In addition to this armament, it contained two bombproofs.”

verb

1. (transitive)To make resistant to bomb blasts.