Geggin is carny slang for man. Another synonym for man is pilot.
-ten the geggin's SG lumpy" means check out that guy's solid gold wristwatch.
Geggin can mean many things. Though, it is also thought of as an unknown color that does not exist. That's just a theory as to what it can mean, as the true meaning is unknown.
"I WANNA PAINT MY FOOT GEGGIN!"