air pollution n.
Contamination of air by smoke and harmful gases, mainly oxides of carbon, sulfur, and nitrogen.
The addition of harmful chemicals to the atmosphere. The most serious air pollution results from the burning of fossil fuels, expecially in internal-combustion engines.
| an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle. |
| a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison. |