Breasts with an almost supernatural jiggle. Like water wrapped in a thin layer of skin. Not necessarily attached to a fat woman, and more common in physically active women who have jogged the firmness out of their chest pillows. Rippling is noticeable with even the slightest movement. When unsupported, they sag and flatten out to the shape of the ribcage from which they hang.
I saw this chick with a low-cut top and water boobs biking down the street. She was hitting potholes left and right. I couldn't NOT stare.