Demand means to ask for something firmly and forcefully, expecting to get it. When you demand an answer, you're insisting with authority or urgency. A teacher might demand silence in a chaotic classroom. A detective might demand the truth from a suspect. Parents might demand that their children clean their rooms immediately.

The word carries a tone of seriousness and expectation. Demanding something suggests you believe you have a right to it or that the situation is urgent enough to require it. If you simply asked your friend to return your book, that's a request. If you demand it back because they've had it for months, you're being much more forceful.

As a noun, demand can mean a firm request: “Their demand was clear.”

In economics, demand takes on a different meaning: the desire and ability to buy something. When there's high demand for a new video game, lots of people want to buy it. When demand for strawberries drops in winter, fewer people are buying them. Businesses pay close attention to demand because it helps them decide what to make and how much to charge. If demand for something goes up while supply stays the same, prices usually rise. If demand falls, prices typically drop.

The word can also describe something that requires effort or attention: a demanding math problem takes serious concentration, and a demanding coach expects excellent performance from every player.