belly flap
used to discribe a woman with a scar from a C section
dude did you see that belly flap walk by
Belly flap clap
When a person has loose belly skin, such as after pregnancy or extreme weight loss, and does an activity such as jumping or running, causing the extra skin flap to clap against the person.
Losing100_facefree has loud belly flap clap in her IG videos because of her extra belly skin after losing so much weight.