Volatile is a word meaning, roughly, "temporary" or "fickle". It has specific meanings in several fields:

In economics:

• Volatility is a measure of the risk in a financial instrument

In chemistry, a volatile substance evaporates at a relatively low temperature:

• Volatile organic compounds evaporate at normal temperatures and pressures
• Volatile anaesthetics are a class of anaesthetics which evaporate easily
• Volatile substance abuse is the abuse of household inhalants containing volatile compounds
• Volatile oil is another name for "essential oil"
• Volatile acidity is an unacceptably high level of acid or vinegar, in winemaking

In computer science:

• Volatile variables can be changed by external processes
• Volatile memory holds items in memory only while power is on

In geology:

• Volatiles are the volatile compounds of magma (mostly water vapor), which plays an important part in the strength and appearance of a volcano.

Volatile