(noun) excessively large breast implants. Usually referenced as such when they are paired with revealing and tight fitting support clothing that pushes them up and out to cause them to form a nearly flat surface on top.
Most prevalent with larger women that choose to get DD+ breast implants to compensate/compliment their fuller figure.
"She is dumb as a box of rocks, but she is redeemed by the stunt bags (she has)."
"With hips like those, she could really use a pair of stunt bags to round out her figure."