Volatile

Definition

Volatile is primarily an adjective meaning prone to rapid or unpredictable change; unstable. In science, it describes a substance that evaporates readily at normal temperatures. In finance and statistics, it denotes high variability. As a noun (often plural), it refers to a volatile substance or to compounds with low boiling points (e.g., planetary or geological volatiles).

Parts of Speech

• Adjective
• Noun (countable; chiefly scientific, often plural volatiles)

Pronunciation

American English

• IPA: /ˈvɑːlətaɪl/
• Respelling: VOL-uh-tyle

British English

• IPA: /ˈvɒlətaɪl/
• Respelling: VOL-uh-tyle

Etymology

Late Middle English: from Old French volatil, from Latin volatīlis “winged, swift, fleeting,” from volāre “to fly.” The sense of “readily evaporating” arose by comparison to things that “fly off” into vapor.

Derivatives

• volatility (noun) — the quality of being volatile; in finance, a measure of price variability
• volatilely (adverb) — in a volatile manner (rare)
• volatilize / volatilise (verb) — to make or become volatile (chem.); convert to vapor
• volatilization / volatilisation (noun) — the act or process of becoming vapor
• nonvolatile (adjective) — not readily evaporating; also “non-volatile memory” (computing)
• volatiles (plural noun) — substances with low boiling points (e.g., H₂O, CO₂, NH₃ in planetary science)

Synonyms

• unstable
• unpredictable
• explosive
• fickle
• mercurial
• skittish
• evaporative (scientific sense)
• high-variance (finance/statistics, attributive)

Antonyms

• stable
• steady
• predictable
• consistent
• calm
• placid
• nonvolatile (scientific/technical)

Usage

General: Often modifies situation, mix, region, relationship, mood. In finance: volatile markets/prices/assets. In science: volatile compounds, volatile organic compounds (VOCs). In computing: volatile memory; in programming (C/C++/C#), volatile is a keyword with a technical meaning.

• “The post-election climate remained highly volatile.”
• “Tech stocks were unusually volatile throughout the quarter.”
• “Acetone is a volatile solvent that evaporates quickly.”
• “DRAM is volatile memory and loses data when power is removed.”

Related Terms

• Volatility: Degree of variation (e.g., standard deviation of returns); general instability.
• VOCs (volatile organic compounds): Organic chemicals with high vapor pressure at room temperature.
• Non-volatile memory (NVM): Storage that retains data without power (e.g., flash).
• Volatilize: To convert to vapor; to cause to evaporate.
• Mercurial: Quick, changeable in temperament (semantic overlap with personality sense).

Detailed Definitions

Adjective

• Prone to rapid, unpredictable change; unstable or explosive (of situations or conditions).
  • Example: “The ceasefire created a volatile peace that could collapse at any moment.”
• Changeable or mercurial in mood or temperament (of persons or groups).
  • Example: “His volatile temperament made negotiations delicate.”
• (Chemistry/Physics) Readily evaporating at normal temperatures; having a low boiling point.
  • Example: “Diethyl ether is highly volatile and must be handled in a fume hood.”
• (Finance/Statistics) Exhibiting large short-term fluctuations; characterized by high variability.
  • Example: “Small-cap equities tend to be more volatile than large-cap stocks.”
• (Computing) Dependent on continuous power to retain stored information (of memory).
  • Example: “Cache and main memory are volatile, whereas SSDs are non-volatile.”

Noun

• (Chemistry/Geoscience) A substance that vaporizes readily; collectively, compounds with low boiling points.
  • Example: “Cometary volatiles such as water and carbon dioxide sublimate near the Sun.”