If you waste something such as time, money, or energy, you use too much of it doing something that is not important or necessary, or is unlikely to succeed.

Waste is the use of money or other resources on things that do not need it.

Waste is material which has been used and is no longer wanted, for example because the valuable or useful part of it has been taken out.

If you waste an opportunity for something, you do not take advantage of it when it is available.

If you say that something is wasted on someone, you mean that there is no point giving it or telling it to them as they will not appreciate, understand, or pay any attention to it.

Waste land is land, especially in or near a city, which is not used or looked after by anyone, and so is covered by wild plants and rubbish.

Wastes are a large area of land, for example a desert, in which there are very few people, plants, or animals.

If something goes to waste, it remains unused or has to be thrown away.

If something or someone lays waste an area or town or lays waste to it, they completely destroy it.

The expression waste not, want not means that if you do not use too much of something now you will have some left later when you need it.