Carpool means sharing car rides with others who are traveling to the same place, like when several families take turns driving their kids to school instead of each parent driving separately every day. A typical carpool arrangement might have one parent drive on Mondays and Tuesdays, another on Wednesdays and Thursdays, and a third on Fridays.

Carpooling saves time, money, and reduces traffic. Instead of five cars clogging the school drop-off lane, one car carries five students. Parents save on gas and wear on their vehicles while getting back hours they'd otherwise spend driving. Many cities have special carpool lanes on highways where cars with multiple passengers can travel faster, rewarding people who share rides.

The word works as a verb too: “We carpool to soccer practice” or “Can you carpool with us tomorrow?” Some workplaces organize carpools for employees who live near each other, and environmental groups promote carpooling as a way to reduce pollution.

You might also hear about vanpools, which work the same way but use larger vehicles to carry more people, or ridesharing, a modern term that includes both traditional carpools and services where people share rides through smartphone apps.