I don't think it necessarily HAS to be a nickname for anything - it could work fine on its own.
I can see it working as a NN for any name ending with "-dy/-die" =
Cody,
Brady,
Grady,
Brody,
Andy,
Cassidy,
Geordie, Bodhi,
Kennedy,
Rudy,
Woody, etc.
This message was edited 1/13/2012, 3:21 PM