Spring-jiggle

Spring jig-gle (N, V, Adj.)
1. Associated with a pudding (31), teardrop or heart-shaped ass. The snapping back of healthy, female, gluteus maximus muscle.
2. A supple ass with strong support ties or extreme foundational integrity. The behind the scenes, working mechanisms, of the finished result.
3. Often referred to as the Spring-jiggle Effect, primarily in a gym environment. It is believed that certain exercises can amplify the desired outcome. Heredity, however, is given a large portion of the credit. Brazilian and Colombian ass is usually a visual marker of the Effect.

“If you want, I can show you some exercises to enhance your spring-jiggle.”
“My what?” I said, laughing.

Origin: J. Bango book series—“Dorm Tramps.”