What does excrete mean?
To excrete is to separate and eliminate waste matter from the body or from a living cell. In humans and animals this includes urine, carbon dioxide, sweat, and faeces, discharged through organs such as the kidneys, lungs, skin, and intestines; plants and single-celled organisms also excrete metabolic by-products. The word belongs chiefly to scientific register — biology textbooks and medical writing use it routinely, while everyday conversation favours gentler phrasing — yet it remains the precise, neutral term whenever accuracy matters. Its opposite in function is "secrete," which describes producing and releasing useful substances like hormones or enzymes, and confusing the two is a classic error worth avoiding. Derived from Latin roots meaning essentially to sift out, "excrete" captures the body's elegant filtering work: distinguishing what to keep from what to discard.
verbTo excrete is to discharge waste matter, such as urine, sweat, or faeces, from the body or from a cell or organ; more broadly, to separate and eliminate substance that is no longer needed by an organism.
- To discharge waste matter from the body, a cell, or an organ (the dominant sense in biology and medicine).
- More broadly, for plants or other organisms to release or eliminate substances no longer needed.
"The kidneys filter the blood and excrete excess salts through the urine."
"Marine birds have specialized glands that excrete excess salt from their bodies."
"The bacteria excrete lactic acid as a by-product of fermentation."
The same Latin root that gave us "excrete" also gave us "discern" and "secret" — all trace back to the act of sifting, as if the body were sorting grain from chaff.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of excrete
Excrete comes from Latin excretus, the past participle of excernere, formed from ex- (out) and cernere (to sift or discern). The underlying image is one of sifting — separating waste from what the organism needs to keep. It entered English in the early seventeenth century alongside related terms such as "excretion" and "excrement." It shares this Latin root with words like "secrete," "secret," "discrete," and "discern," all descendants of the sifting metaphor.
Related word forms
How excrete is actually used
"Excrete" is a formal, scientific term, standard in biology and medicine but clinical-sounding in everyday speech, where euphemisms like "pass" are preferred. It carries no moral connotation and refers strictly to the elimination of unwanted substances — unlike its near-opposite "secrete," which describes releasing useful products.
Easily confused with excrete
"Secrete" means to produce and release a useful substance such as a hormone or enzyme, while "excrete" means to pass out waste matter from the body.