Half chav, half melon; a person who claims to be a chav but is known for his abnormally large head
Most people think of a Sam Hulme when mentioning such a thing. Many who haven't met this person already dislike him simply because he is a complete dickhead... and his rather large head of course
1. Sean: "Oh my god sam, you're such a prick!"
Jake: "Yeah, you CHELON!"
Sean: "Tell me about it"
2. Sam: "What's wrong with my head?"
Sean: "What isn't wrong with your head?"
Josh: "It's a MELONHEAD!