A small hatchet or ax with a short handle, or something shaped like a hatchet that's positioned at the back or rear.
From hatchet (a small ax, from Old French hachette, diminutive of hache meaning ax) + back. The term is less common than hatchback in modern usage.
Some old ship designs had a 'hatchet back' stern—a sharp, squared-off back that looked like a hatchet blade—which actually made ships more hydrodynamic than the rounded sterns that became popular later!
Complete word intelligence in one call. Free tier — 50 lookups/day.