waste product

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An unusable or unwanted substance or material produced during or as a result of a process, such as metabolism or manufacturing.

The products of metabolic activity after oxygen and nutrients have been supplied to a cell. These include primarily carbon dioxide and water, along with sodium chloride and soluble nitrogenous salts, which are excreted in feces, urine, and exhaled air.

Products of metabolism that are eliminated from the body. Some waste products, such as lactic acid, may be harmful if they accumulate in the body. See also excretion.

1. Useless or worthless debris produced during or as a result of an activity or other process.
2. Organic waste matter such as urine, feces, or dead cells.

The noun has one meaning:

Meaning #1: any materials unused and rejected as worthless or unwanted
  Synonyms: waste, waste material, waste matter