Definition of bulletproof
1
: impenetrable to bullets
bulletproof glass
2
: not subject to correction, alteration, or modification
a bulletproof argument
3
: invincible
Keep scrolling for more
Keep scrolling for more
Keep scrolling for more
Keep scrolling for more
Test Your Vocabulary
The Exceptions Quiz III
-
- Which of these words does not mean "nonsense"?

Test your visual vocabulary with our 10-question challenge!
TAKE THE QUIZ
Anagram puzzles meet word search.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridged
Words at Play
Ask the Editors
Share bulletproof
Time Traveler for bulletproof
The first known use of bulletproof was in 1693
See more words from the same year