bombproof

Etymology

bomb + -proof

adj

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

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. 1915, Edward Lyell Fox, Behind the Scenes in Warring Germany
   At night, when the Federal guns slowed their fire, the men created new traverses and bombproofs. 1994, Stephen R. Wise, Gate of Hell: Campaign for Charleston Harbor, 1863, page 160
   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. 2014, Kevin Dougherty, Military Leadership Lessons of the Charleston Campaign, 1861-1865

verb

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