bulletproof

• bullet-proof

From bullet +‎ -proof.

• IPA^(key): /bʊl.ɪtpɹuːf/

• Audio (General Australian):

  (file)

• Hyphenation: bul‧let‧proof

bulletproof (comparative more bulletproof, superlative most bulletproof)

1. (of a material) Capable of withstanding a direct shot by a bullet fired from a gun.

   bulletproof window

   bulletproof vest

   • 2023 May 16, “YouTube and Gun Content: A Dangerous Combination for Kids and Teens”, in Everytown Support Fund‎:

     YouTube is awash in gun content, often referred to as “GunTube” by firearm enthusiasts. Individuals who come to GunTube—including children and teens—can find videos which glorify assault weapons, show how to modify firearms, and teach viewers how to shoot through bulletproof glass or “win gunfights.”

2. (figurative) Reliable, infallible, sturdy or error-tolerant.

   bulletproof hosting

   • 2018 September 20, Graeme Virtue, “Shania Twain review – barnstorming, thigh-slapping spectacular”, in The Guardian‎:

     The packed opening night of Twain’s first UK tour since 2004 is an impressively barnstorming, thigh-slapping, eye-searing revue that marries her bulletproof back catalogue with a cautious sprinkle of new material.

   • 2020 December 9, Ezra Marcus, “Tone Is Hard to Grasp Online. Can Tone Indicators Help?”, in The New York Times‎, archived from the original on 4 July 2021:

     But what tone indicators lack in artfulness, they make up for in their bulletproof inability to be misinterpreted.

• (infallible): foolproof

bulletproof (third-person singular simple present bulletproofs, present participle bulletproofing, simple past and past participle bulletproofed)

1. To make proof against bullets.
2. (slang) to make 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.