Slag (noun)

1. Waste material, especially from a mining process or a metal smelting process.
2. A woman of loose morals.
3. Insults or criticisms towards someone.

Origin:

From middle english slaygh, meaning "dross" or "waste".

Examples:

1. The slag from the smelting process was used to make roads.
2. He called her a slag, because she had slept with multiple men.
3. The miners were covered in slag from the mining process.
4. The slag heap was a constant eyesore in the town.
5. The term "slag" is considered derogatory and offensive, and should be avoided.