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

Idaho sewage treatment plants aren’t supposed to release pollutants like these into the water — but over half of them did last year, according to a recent report from the Idaho Conservation League. — Sarah Cutler, Idaho Statesman, 4 Sep. 2026

Temperatures are at record highs, currents are shifting and stronger storms wash more pollutants into the water, including sewage and fertilizers, which can trigger huge algae blooms. — Laura Paddison, CNN Money, 4 Sep. 2026

Persistent organic pollutants are toxic organic chemicals, usually synthetic but occasionally occurring naturally, that resist environmental degradation, persist in the environment for decades, and can be transported over long distances. — Encyclopedia Britannica, 3 Sep. 2026

People who may be especially sensitive to the effects of elevated levels of pollutants include the very young and those with preexisting respiratory problems such as asthma or heart disease. — Kansas City Star Weather Bot, Kansas City Star, 1 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