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

Residents who want to check the air quality in their neighborhood can go to the Open Air Chicago map and click on a sensor nearest to their location to find readings on pollutants. — Finnegan Belleau, Chicago Tribune, 26 July 2026

America’s version of the AQI was first created 50 years ago, as a way to standardize recording and reporting of pollutants and to clarify communications to the public. — Daniel Engber, The Atlantic, 24 July 2026

The signature blend of ceramides works to strengthen and support the skin’s natural barrier, which helps lock in moisture while defending against environmental irritants like pollutants and allergens. — Alicia Geigel, Southern Living, 23 July 2026

This helps limit continued exposure to pollutants that are hard to get out. — Faith Wakefield, USA Today, 20 July 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