Word parts change

bullet + -proof

Pronunciation change

Adjective change

Positive
bulletproof

Comparative
more bulletproof

Superlative
most bulletproof

 
Testing a bulletproof vest 1923
  1. A bulletproof material is something that can resist a direct shot by a bullet fired from a gun.
    The police officers are wearing bulletproof vests.
  2. If an idea or concept is bulletproof, it is unbreakable, very tough.

Verb change

Plain form
bulletproof

Third-person singular
bulletproofs

Past tense
bulletproofed

Past participle
bulletproofed

Present participle
bulletproofing

  1. (transitive) If you bulletproof something, you make it able to resist bullets.
    The engineers are trying to bulletproof the president's vehicle now.
  2. (transitive) (slang) If you bulletproof something, you make it resistant to failure.
    We have to bulletproof this program before we let the users at it; check every input, catch every possible flaw … it must not fail in use.