Origin: Germanic Old English prefix
Belly has 8 different meanings across 2 categories:
the underpart of the body of certain vertebrates such as snakes or fish
"The snake slid through its belly to escape from the trap."
The abdomen, especially a fat one.
"After eating too much ice cream, he patted his round belly to check if it was full."
In plain English: The belly is your stomach, which holds all of your food and drinks inside you.
"After eating too much pizza, he had to rub his belly before going for a walk."
Usage: Use the noun belly specifically when referring to an overweight or protruding stomach rather than just any part of the torso. Avoid using it as a verb unless you are describing the specific action of lying prone on your stomach.
To position one’s belly; to move on one’s belly.
"The cat crawled across the floor, dragging its body so that it was moving entirely on its belly."
In plain English: To belly means to move quickly and clumsily, usually by rolling on your stomach while running away from something dangerous or scary.
"The whale began to belly up onto the sand, leaving its massive body exposed in the shallow water."
The word belly comes from Old English bielġ, which originally meant a bag or pouch. It traces its roots back to the Proto-Indo-European root *bʰelǵʰ-, meaning "to swell" or "blow up."