Volatile

Part of speech: adjective

Pronunciation: /ˈvɒl.əˌtaɪ.(ə)l/

Definitions

1. Liable to change rapidly and unpredictably, especially for the worse, or capable of evaporating quickly at normal temperatures
2. Subject to rapid or significant change, often in a harmful way, and characterized by a tendency to easily transform from liquid to gas at average temperatures
3. Inclined to fluctuate sharply or unpredictably, particularly in negative contexts, while also being able to swiftly transition from a liquid state to vapor under standard conditions

Etymology: The adjective "volatile" began as a description of things that literally flew. Its Latin ancestor, "volatilis," meant "flying" or "swift," and it came from "volare," "to fly." Medieval writers borrowed the idea into Middle French as a word for things that could rise into the air, and the sense of quickly vanishing or departing followed naturally from that image of flight. That sense of escaping into the air is what made the word useful to alchemists and early chemists, who applied it to substances that turned readily into vapour when heated. From there, "volatile" moved into English with that physical meaning intact. The jump from a bird or a cloud to a volatile mood or market is a short one: both describe something that can change state or position with little warning.

Synonyms: unstable, fickle, changeable, explosive, inconstant

Antonyms: stable, steady, constant, reliable, predictable