A complex arrangement of metal parts that is capable of discharging a lead peice at very high speeds, high enough to penetrate fleash and thin slabs of wood. Serves as humankind's (so far) permanent replacement for spears, staffs, swords, daggars, etc. as most effective weapons. Most commonly used for self-defense, murder, killing hostiles, recreational shooting, the standard issue weapons for armies, militias, etc.
Guns aren't the problem. It's criminals, irresponsible people, and totalitarian shitheads getting a hold of them that's the problem.