What does excretion mean?
Excretion is the biological process by which an organism eliminates waste products generated by its own metabolism. In humans and many animals this is carried out primarily by organs such as the kidneys, lungs, skin, and liver, which remove substances like urea, carbon dioxide, salts, and excess water. The term can also denote the waste material itself — what has been excreted. Derived from Latin roots meaning 'to sift out' or 'to separate', the word entered English in the early seventeenth century and remains largely confined to scientific, medical, and educational contexts. It should not be confused with secretion, which describes the release of useful substances such as hormones or enzymes rather than waste. Understanding excretion is fundamental to physiology: it explains how organisms maintain internal balance, dispose of potentially toxic compounds, and regulate water and mineral levels. Though unglamorous, the word names one of the essential processes that keep every living thing alive.
The process of eliminating waste matter produced by metabolism from the body of an organism.
"Efficient excretion of nitrogenous waste is essential to an animal's survival."
Primarily used in scientific and medical registers.
Waste matter discharged from the body or from a cell.
"The larvae's excretion accumulated at the bottom of the container."
The plural typically refers to multiple instances or types of waste matter discharged.
"The laboratory analysed various excretions collected from the samples."
Every second of your life, your kidneys are quietly performing excretion — filter enough blood and you'd fill a small swimming pool with filtrate in a day, nearly all of it reabsorbed.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of excretion
Excretion derives from Latin 'excretio', formed from 'excernere', meaning to sift out or separate, combining 'ex-' (out) with 'cernere' (to sift, discern). The term passed into English in the early seventeenth century, initially in medical writing describing the elimination of bodily wastes. It shares its root with related words such as 'secrete' and 'concrete', all tracing back to the Latin verb 'cernere'.
Related word forms
How excretion is actually used
Excretion is a formal, technical term used chiefly in biology, medicine, and physiology; in everyday speech, words like 'getting rid of waste' are more common. It carries no emotional connotation itself but refers to material often considered unpleasant, so it tends to appear in clinical or scientific contexts.
Easily confused with excretion
Secretion is the production and release of useful substances (such as enzymes or hormones) by a gland, whereas excretion is the discharge of metabolic waste from the body.