bombproof vs protected

bombproof

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

verb
  • To make resistant to bomb blasts. 

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

protected

adj
  • defended 

  • Having the protected access modifier, indicating that a program element is accessible to subclasses but not to the program in general. 

How often have the words bombproof and protected occurred in a corpus of books? (source: Google Ngram Viewer )