volatile

Likely to change suddenly or become angry, violent, or dangerous quickly.

• The situation remains volatile.
• His volatile temper makes people nervous.
• Prices have been volatile since the crisis began.

Similar words: unstable, unpredictable, changeable

Opposites: stable

Common phrases: a volatile situation, volatile markets, a volatile temper

Changing easily from a liquid or solid into a gas.

• Alcohol is a volatile liquid.
• Keep volatile solvents in closed containers.
• Heat causes the volatile compounds to escape into the air.

Opposites: nonvolatile

Common phrases: volatile liquids, a volatile solvent, volatile compounds

A programming variable whose stored value must be read or updated directly because it may change unexpectedly.

• The compiler treats this variable as a volatile.
• Reading a volatile retrieves its current stored value.
• This hardware register is represented by a volatile.

Common phrases: declare a volatile, read a volatile, write a volatile