Volatile means something changing or changeable. It can refer to:
- Volatility (chemistry), a measure of the tendency of a substance to vaporize. It has also been defined as a measure of how readily a substance vaporizes.
- Volatiles, a group of compounds with low boiling points that are associated with a planet's or moon's crust and/or atmosphere
- Volatile liquids, liquid with a high vapor pressure or low boiling point
- Volatile organic compounds, organic compounds that can evaporate at normal temperature and pressure, and are often regulated by governments
- Volatile anaesthetics, a class of anaesthetics which evaporate easily
- Volatile substance abuse, the abuse of household inhalants containing volatile compounds
- Volatile oil, also known as essential oil, an oil derived from plants with aromatic compounds used in cosmetics and flavoring
- Volatile acidity, a term used in winemaking to indicate an unacceptably high level of acid or vinegar and baking soda.
In computer science:
- Volatile variables, variables that can be changed by an external process
- Volatile memory, memory that lasts only while the power is on (and thus would be lost after a restart)
- Volatiles, the volatile compounds of magma (mostly water vapor) that affect the appearance and strength of volcanoes