The Bertle is a rotund, pear like torso. It's not until you see the Bertle 'front on' does one understands the extent of 'over weight' which stretches out from the stomach to the love handles (or belly ears).
The bertle is a more solid and structured belly fat.
This is why, against the laws of gravity, the belly weight does not 'overhang' the waist line, instead it curves upward, like the base of a wine glass.
Example 1:
You look sooooooo bertle in that jacket Bro. With all that belly in your pockets, there'll be no room left for your cash... or confidence.
Example 2:
A: That hoe is so fat!!
B: Some respect dude, pies bow to that bertle!