A catapult is a large mechanical device that uses stored energy to launch objects through the air with great force. Ancient armies used catapults to hurl heavy stones, flaming projectiles, or other missiles at enemy fortifications during sieges. By pulling back a wooden arm with ropes or springs, soldiers stored up energy, then released it all at once to send their ammunition flying hundreds of feet. Some catapults could launch stones weighing 300 pounds or more.

The most famous type of catapult is the trebuchet, which used a heavy counterweight to swing its throwing arm. Medieval castles kept catapults for both attack and defense. When gunpowder weapons like cannons arrived in the 1400s, they eventually replaced catapults in warfare.

Today, aircraft carriers use steam-powered catapults to catapult fighter jets off their short runways, accelerating them to flying speed in just two seconds. The word also works as a verb meaning to launch something suddenly and powerfully, or to advance rapidly. A successful first novel might catapult an unknown writer to fame, and a gymnast might catapult herself off the vault.

You can build a simple catapult using a spoon, popsicle sticks, and rubber bands to launch marshmallows or small erasers across a room. Just be sure to aim safely and never launch anything that could hurt someone.