Waste

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Waste (or wastes) are unwanted or unusable materials. Waste is any substance that is discarded after primary use or is worthless, defective, and of no use.

It may be no longer useful as it has served its purpose, and at the end of the process have no further use, and is generally discarded. It is unwanted material that people have thrown away. It is often also called trash, garbage, rubbish, or junk. It can be solid, liquid, or gas, or it can be waste heat. There are many different kinds of waste. Garbage is the waste we produce daily in our homes, including old or unwanted food, chemical substances, paper, broken furniture, used containers, and other things.

When waste is a liquid or gas, it can be called an emission. This is usually pollution. Sanitation is the proper handling of human waste.

Waste can also be something abstract (something that you cannot touch), for example, "a waste of time" or "wasted opportunities". When people use the words waste or wasted in this way, they are saying (directly or indirectly) that something has been used badly (using too much of it or using it incorrectly).