A cud is a variation of a die defect in which the coin bears a raised portion of metal. Unlike a die crack or die chip, this unintentional "bump" in the coin is caused by a dent or gouge in the die, therefore allowing the coin to fill into the gap during the minting process.A very minuscule cud can look like a small chunk of metal that was somehow fused to the coin. Some numismatists disagree that these small disturbances, although produced in the same way as a cud, can qualify as one.A prominent cud looks like a blank section of a coin, usually toward the rim of the coin.