Goldpiece is a term used to describe a large and glorious "shlong".
It can also be used to describe an obnoxiously large golden medallion or other form of "bling".
I have even heard men refer to their slam pieces as "Goldpiece", however this only works when the slam is of great quality and "slamability". She would preferably be at least a 9.
"have you seen Johns Goldpiece? It was amazingly glorious."
"yo bro check out my new goldpiece, I got it for the Little Wayne concert. It weighs 5.23 pounds"
"Brah you gotta check out my new Goldpiece she's easily a 9.5 in and out of bed, I even thought about dating her but the sandwiches she makes taste like sh**".