volatile

adj

1. Evaporating or vaporizing readily under normal conditions.
2. (informal)Of a substance, explosive.
3. Of a price, variable or erratic.

   “Its pricing is highly volatile — and therefore highly risky. For all its nosebleed ascents, bitcoin also has had some gut-punching plunges. Between November 2021 and November 2022, for example, the price of bitcoin dropped 75%, from $64,455 to $16,196, according to data on coinmarketcap.com.”

4. Of a person, quick to become angry or violent.

   “a volatile man”

5. Fickle.

   “Now Mr. Bush plans to pour more arms into this unstable region and add fuel to the volatile powderkeg he has foolishly created.”

6. Temporary or ephemeral.
7. Of a situation potentially violent.
8. Of a variable etc., having its associated memory immediately updated with any changes in value.

   “This method stores a value into a non-volatile field called result, then stores true in the volatile field finished. The main thread waits for the field finished to be set to true, then reads the field result.”

9. Of memory, whose content is lost when the computer is powered down.
10. (obsolete)Passing through the air on wings, or by the buoyant force of the atmosphere; flying; having the power to fly.

noun

1. A chemical or compound that changes into a gas easily.
2. A variable that is volatile, i.e. has its associated memory immediately updated with any change in value.

   “Operations on C++ volatiles do put the compiler on notice that the object may be modified asynchronously, and hence are generally safer to use than ordinary variable accesses.”