Rodney

It a Insult, to say someone is a "Rodney" is calling them a "Plonker"

Saying they are stupid, dumb, thick

ect...

Derrived from Only Fools & Horses
Dell Boy

"Rodney you 24 carat Plonker"

Yoûû.. "Rodney"

Your as thick as two short "Rodney's"