Search the Dictionary:
Courtesy NASA.gov
aerosol:
A fine spray or mist of liquid or solid particles suspended in a gas. Examples of aerosols are smoke (solid particles in air), and fog and clouds (liquid particles in air). Commercial aerosol cans contain a substance such as paint or cosmetics and a propellant gas under high pressure. When you push the button on top of the can, a valve opens up and the pressure forces the propellant and the substance to spray out from a fine nozzle.