noun | frawd proof
A fraud proof is like when you catch your little brother with his hand in the cookie jar and you have the security camera footage to prove it - it's a cryptographic proof that shows a blockchain transaction is invalid or fraudulent, without having to reveal the details of the transaction itself. It's like snitching on someone, but with math.
Example
"I was running a full node on the Bitcoin network and I found a block with a bunch of fake transactions in it. Submitted a fraud proof to the network and got a fat bounty for my troubles. Snitches get riches, amirite?"
"Fraud proofs are like the 'pics or it didn't happen' of the blockchain world - if you can't prove that a transaction is fake, then it may as well be legit. It's like trying to convince your mom that your dog ate your homework, but instead of a half-chewed book report, it's a cryptographically-signed message from a malicious actor."
