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

As whole house fans and swamp coolers can suck additional pollutants inside, the department recommends using air purifiers or air conditioners as alternatives when possible. — Corinne Purtill, Los Angeles Times, 4 July 2026

The material can power reactions such as oxidizing organic molecules, potentially degrading pollutants, sterilizing surfaces, or enabling photocatalytic chemistry to continue later in the dark. — New Atlas, 3 July 2026

Furthermore, capturing stormwater runoff helps protect the environment by preventing soil erosion and keeping pollutants out of local waterways. — Sj McShane, Martha Stewart, 3 July 2026

The uninterrupted sun dries out soil increasing drought risk, and light winds allow pollutants to build up, worsening air quality, particularly in urban areas. — Janet Loehrke, USA Today, 1 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