bulletproof: meaning, definition, pronunciation and examples
C1Informal to formal, depending on context (technical in security/military; metaphorical in business/tech).
Quick answer
What does “bulletproof” mean?
Impervious to bullets.
Audio
Pronunciation
Definition
Meaning and Definition
Impervious to bullets; physically resistant to penetration.
Incapable of being damaged, broken, defeated, or disproven; extremely reliable or secure.
Dialectal Variation
British vs American Usage
Differences
No significant difference in meaning. Spelling is consistently 'bulletproof' (one word). Frequency of metaphorical use is similar.
Connotations
Both share connotations of ultimate protection, reliability, and resilience.
Frequency
Slightly more frequent in American media/corporate jargon (e.g., 'bulletproof strategy').
Grammar
How to Use “bulletproof” in a Sentence
bulletproof + noun (adj.)make + object + bulletproof (verb)be + bulletproof + against + threatVocabulary
Collocations
Examples
Examples of “bulletproof” in a Sentence
verb
British English
- They bulletproofed the royal limousine for the visit.
- We need to bulletproof our servers against cyber attacks.
American English
- The company bulletproofed the contract with additional clauses.
- He bulletproofed his truck for off-road security.
adverb
British English
- The cabin was constructed bulletproof. (rare)
American English
- The system is designed bulletproof. (rare)
adjective
British English
- The journalist wore a bulletproof vest in the conflict zone.
- Their alibi was not entirely bulletproof.
American English
- The CEO demanded a bulletproof argument for the merger.
- This glass is advertised as bulletproof.
Usage
Meaning in Context
Business
A plan or contract designed to be legally unassailable.
Academic
Used metaphorically to describe a theory or methodology resistant to criticism.
Everyday
Describing something very reliable or strong, like a phone case.
Technical
Refers to materials or systems designed to stop ballistic projectiles.
Watch out
Common Mistakes When Using “bulletproof”
- Using 'bulletproof' as a noun (e.g., 'He wore a bulletproof' – incorrect; must be 'bulletproof vest'). Overusing the metaphorical sense in formal technical writing.
FAQ
Frequently Asked Questions
Yes, informally, meaning 'to make bulletproof' or 'to make invulnerable' (e.g., 'bulletproof a system').
'Bulletproof' emphasises resistance to attack or damage. 'Foolproof' emphasises simplicity and reliability, so that even a fool cannot misuse it.
It is accepted in business and tech contexts but can be considered slightly informal in strict academic or legal prose.
Using it as a standalone noun instead of an adjective (e.g., saying 'He put on his bulletproof' instead of '...bulletproof vest').
Impervious to bullets.
Bulletproof: in British English it is pronounced /ˈbʊlɪtpruːf/, and in American English it is pronounced /ˈbʊlɪtpruːf/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “A bulletproof vest (literal); a bulletproof alibi (metaphorical).”
Learning
Memory Aids
Mnemonic
Think of 'proof' as in 'proof against' (resistant to) + 'bullet' = resistant to bullets.
Conceptual Metaphor
PROTECTION IS A PHYSICAL BARRIER / RELIABILITY IS PHYSICAL STRENGTH.
Practice
Quiz
In which context is 'bulletproof' LEAST appropriate?