pollutant

noun

pol·​lut·​ant pə-ˈlü-tᵊnt 

plural pollutants

: something that pollutes

especially : something (such as waste created by human activity) that makes an environment unsuitable or unsafe for use

sources of pollutants [=pollution] in the environment

Meanwhile, scientists warned that other air pollutants—especially from automobiles—might also be contributing to health problems, forest damage and decreased crop production.

—National Wildlife

Formaldehyde is an important atmospheric pollutant that can be produced in photochemical smog.

—Des W. Connell

A 165-foot cement tower contains radium-rich blends that have given off radon gas—a pollutant that can cause cancer.

—Michael H. Brown

Synonyms of pollutant

• contaminant
• contamination

Examples of pollutant in a Sentence

filtered the pollutants out of the water

Recent Examples on the Web

Wild salmon, for example, may sound healthier, but its liver, kidneys, intestines, head and skin store more chemical pollutants than the rest of the fish. — Sandee Lamotte, CNN Money, 2 Oct. 2026

Though ozone high up in Earth’s stratosphere provides protection from ultraviolet radiation to people and other life on the planet, ground-level ozone is a toxic pollutant. — Mary Randolph, Scientific American, 30 Sep. 2026

Their presence raises concerns that a system designed to salvage nutrients can also recycle pollutants. — Edward D. Melillo, The Conversation, 30 Sep. 2026

The researchers said ground-level ozone, a pollutant that develops when specific pollutants react with sunlight and high temperatures, harms human health, ecosystems and crop yields. — Dan Peck, ABC News, 29 Sep. 2026

Word History

First Known Use

1892, in the meaning defined above

Rhymes for pollutant

• disputant
• mutant

Kids Definition

pollutant

noun

pol·​lut·​ant pə-ˈlüt-ᵊnt 

: something that pollutes

Medical Definition

pollutant

noun

pol·​lut·​ant pə-ˈlüt-ᵊnt 

: something that pollutes

especially : something (such as anthropogenic waste) that makes an environment unsuitable or unsafe for use