A knock is when someone hits a door or window to attract someone's attention.

A knock is a firm touch that causes something to fall or move.

If someone receives a knock, they have an unpleasant experience which prevents them from achieving something or which causes them to change their attitudes or plans.

If someone knocks around somewhere, they spend time there, experiencing different situations or just passing time.

If someone knocks you around, they hit or kick you several times.

To knock down a building or part of a building means to demolish it.

To knock down a price or amount means to decrease it.

If someone is knocked down or is knocked over by a vehicle or its driver, they are hit by a car and fall to the ground, and are often injured or killed.

To knock off an amount from a price, time, or level means to reduce it by that amount.

When you knock off, you finish work at the end of the day or before a break.

To knock someone out means to cause them to become unconscious or to go to sleep.

If a person or team is knocked out of a competition, they are defeated in a game, so that they take no more part in the competition.

If something is knocked out by enemy action or bad weather, it is destroyed or stops functioning because of it.

If you knock something up, you make it or build it very quickly, using whatever materials are available.

If a woman is knocked up by a man, she is made pregnant by him.

If you knock on something such as a door or window, you hit it, usually several times, to attract someone's attention.

If you knock something, you touch or hit it roughly, especially so that it falls or moves.

To knock someone into a particular position or condition means to hit them very hard so that they fall over or become unconscious.

To knock a particular quality or characteristic out of someone means to make them lose it.

If you knock something or someone, you criticize them and say unpleasant things about them.