A sock is a soft covering for your foot, usually made of cotton, wool, or synthetic fabric. Socks fit inside your shoes to keep your feet warm, comfortable, and protected from blisters. Most socks come up to your ankle or partway up your calf, though some athletes wear tall socks that reach their knees.

People have worn socks for thousands of years. Ancient Greeks and Romans wore simple cloth wrappings on their feet, while later civilizations knitted more sophisticated versions. Today's socks come in endless varieties: athletic socks with extra cushioning, dress socks for formal occasions, cozy wool socks for winter, and novelty socks covered in patterns or cartoon characters.

The word sock also means to hit something forcefully. A baseball player might sock a home run over the fence, or you might say someone socked their opponent in a boxing match. When something impacts you powerfully, even emotionally, it can sock you: “The ending of that story really socked me.”

You might also hear the phrase “put a sock in it,” which means to be quiet or stop talking. And when something succeeds dramatically, people say it knocked your socks off.