Aerosol

Aerosol is defined as a mixture in which one substance (either a solid or liquid) of microscopically dispersed insoluble particles is suspended in a gas, usually dispensed in a cloud or mist.

An example of an aerosol (inhaler)

Aerosol Medication

Aerosol medications are usually given in different properties and indications which are administered via inhalation. It is commonly used on mechanically ventilated patients.

Resources:

1. Medical Dictionary by thefreedictionary.com
2. Wikipedia 
3. US National Library of Medicine National Institutes of Health