Definition of defy belief
: to be unbelievable : to be not deserving to be believed His story about UFOs defies belief.
Word by Word Definitions
: to challenge to combat
: to challenge to do something considered impossible : dare
: to confront with assured power of resistance : disregard
: challenge, defiance
Seen and Heard
What made you want to look up defy belief? Please tell us where you read or heard it (including the quote, if possible).