A lonely male, usually a teenager, who spends all day, every day, sitting in a darkened room alone, trying his best to make just one of his arms look like Popeye's.
Occasionally one eyed frowning with the sticky out chin comes into play, accompanied by Popeye's "Ugugugug!" chuckling noise.
Often leads to a Popeye style walk in later life.
I called round to see Dave the other day, he's becoming a proper One Armed Popeye.