(adjective, verb)


1. without flaws or loopholes

- a bulletproof argument

Similar word(s): incontestable, incontestible, unassailable, unshakable, watertight

2. not penetrable by bullets

- bulletproof glass

- bulletproof vest

Similar word(s): armored, armoured

Sentences with bulletproof as an adjective:

- A bulletproof window.

- A bulletproof vest.


1. make bulletproof

- bulletproof the car

Definition categories: change, proof

Sentences with bulletproof as a verb:

- 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.