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

This summer has seen record-smashing heatwaves across Europe, huge wildfires from Spain and France to Canada, which have released deadly pollutants into the air, and yet more extreme heat from Africa to Asia. — Catarina Rolfsdotter-Jansson, Forbes.com, 22 Aug. 2026

These fun masks foam up on the skin to remove dirt, oil, debris, and other pollutants that can clog your pores. — Bestreviews, Chicago Tribune, 18 Aug. 2026

Improving raw ore, for instance, involves releasing water that is contaminated with radioactive pollutants, creating health issues for workers and local residents. — Gloria Xiong, Foreign Affairs, 18 Aug. 2026

Our state has thousands of sites already polluted with toxic chemicals and other pollutants, and those projects affect air quality, safe drinking water and community health for millions of Californians. — Shannon Olivieri Hovis, Mercury News, 18 Aug. 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