Belly Gun

Any small, compact, short-barreled pistol, typically a hammerless revolver but could be an automatic in smaller caliber. Easily concealed in a trouser pocket or handbag, it is intended for close-range use, e.g., firing directly into an adversary's abdomen with a minimum of fuss.

Chief Harmon subdued the perp with two quick shots from his belly gun, not even bothering to pull it out of his coat pocket.