
- AIR Definition & Meaning - Merriam-Webster- The meaning of AIR is the mixture of invisible odorless tasteless gases (such as nitrogen and oxygen) that surrounds the earth; also : the equivalent mix of gases on another celestial object … 
- Air | Composition, Oxygen, Nitrogen | Britannica- Sep 12, 2025 · Air, mixture of gases comprising the Earth’s atmosphere. The mixture contains a group of gases of nearly constant concentrations and a group with concentrations that are … 
- Home | American Institutes for Research- AIR applies its decades of workforce research in developing the knowledge, tools, systems, and programs needed to maximize human and organizational potential in the 21st century. 
- Air - Simple English Wikipedia, the free encyclopedia- Air is a mixture of many gases and tiny dust particles. It is the clear gas in which living things live and breathe. It has an indefinite shape and volume. It has mass and weight, because it is … 
- Air - National Geographic Society- Oct 1, 2024 · Air is the invisible mixture of gases that surrounds Earth. Air contains important substances, such as oxygen and nitrogen, that most species need to survive. 
- AIR | English meaning - Cambridge Dictionary- AIR definition: 1. the mixture of gases that surrounds the earth and that we breathe: 2. the space above the…. Learn more. 
- The Chemical Composition of Air - ThoughtCo- Jul 29, 2024 · Nearly all of Earth's atmosphere (air) is comprised of a mere five gases: nitrogen, oxygen, water vapor, argon, and carbon dioxide. Several other compounds are also present in … 
- What is the definition of air? - The Institute for Environmental ...- Jun 19, 2025 · Air is the mixture of gases surrounding the Earth. Wind is simply air in motion, typically caused by differences in air pressure due to uneven heating of the Earth’s surface. 
- What's in the Air? - Center for Science Education- Air is a mixture of gases, most of which are naturally occurring. Air also contains a significant amount of human-made air pollutants, including some that are not safe to breathe and some … 
- AIR Definition & Meaning | Dictionary.com- The terms air or the air is used generally to refer to the sky or open space outside. Real-life example: Airplanes and helicopters are designed to fly in the air, meaning the empty space …