You searched for: “pollution”
pollution (s) (noun) (no pl)
A harmful or otherwise unwanted chemical created when engines burn fuel: Exhaust pollution is a mixture of gases, such as carbon monoxide and solids including soot.

This entry is located in the following unit: Automobile or Related Car Terms (page 5)
pollution, pollutions
1. A condition or situation that is not clean.
2. An environment that is contaminated with harmful substances. (1)
This entry is located in the following unit: Word a Day Revisited Index of Cartoons Illustrating the Meanings of Words (page 62)