Definition of "contaminant" [contaminant]

• One that contaminates. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "To that I would had the SO4 contaminant from the West Virginia powerplants that has obscured the view from the Skyline Drive, and impacts the tourist bidness."
• "Thomas Cech and his group initially attributed the activity of their Tetrahymena RNA to a protein contaminant, and they only slowly succumbed to the weight of the accumulated data that argued for the RNA."
• "The study “still begs the question how much contaminant is left in the paint pit, and I don’t think anyone in the world knows that,” Strange said."