Meaning: tending or threatening to break out into open violence; explosive.

Example: the country was amid a volatile political situation.

Related/similar words: changeable, fluctuating, fluid, inconsistent, inconstant, temperamental, uncertain, unpredictable, unsettled, unstable, unsteady, variable.

Etymology: volatile was originally for the birds—quite literally. Back in the 14th century, volatile was a noun that referred to birds (especially wild fowl) or other winged creatures, such as butterflies. Volatile traces back to the Latin verb volare, which means "to fly”. By the end of the 16th century, people were using volatile as an adjective for things that were so light they seemed ready to fly. The adjective was soon extended to vapors and gases, and by the early 17th century, volatile was being applied to individuals or things as prone to sudden change as some gaseous substances. In recent years, volatile has landed in economic, political, and technical contexts far flown from its avian origins.