A pouch is a small bag or pocket used to carry things safely. A kangaroo carries her baby in a built-in pouch on her belly. You might keep coins in a zippered pouch in your backpack, or carry a pouch of trail mix on a hike.

Many animals have pouches: kangaroos, opossums, and koalas are called marsupials because they raise their tiny newborns in these warm, protective pockets. The babies stay safe inside until they're big enough to face the world.

People use pouches too. Medieval travelers carried leather pouches tied to their belts for coins and small tools. Modern hikers wear pouches on their waists for snacks and phones. A mail pouch holds letters for delivery. Even juice comes in pouches with little straws.

The word also describes anything shaped like a small bag. A pelican has a throat pouch for catching fish. Squirrels sometimes get puffy pouches in their cheeks from stuffing them with nuts.

What makes something a pouch rather than just a bag? Usually its size (small enough to tuck away) and purpose (keeping specific items protected and easy to reach).