What is jiggle?

Jiggle is when a person has a storage fo fat or cellulite in a concentrated area, and when that area moves (IE Running, jumping, or being slapped) it quivers like a bowl of jello would. For Example: * I slapped my girlfriend's ass and it jiggled so much; she's gaining weight. * When she ran, her boobs jiggled up and down. * My sister ate two pots of spaghetti; her potbelly now jiggles with even the slightest contact.