Mercurial
Unpredictably changeable in mood or behaviour, from Mercury (Hermes), the swift and restless messenger god.
The Meaning of Mercurial
Mercury was the Roman name for Hermes, the messenger who raced between Olympus, earth, and the underworld at extraordinary speed. He was the trickster who stole Apollo's cattle on his first day alive, the negotiator who brokered peace, the guide who escorted souls to the afterlife — never still, never predictable, always shifting roles. Medieval astrologers assigned the planet Mercury influence over communication, travel, and change. Those born under Mercury were said to be quick-witted but unreliable, brilliant but volatile. The adjective "mercurial" entered English in the seventeenth century to describe people whose moods and interests shift rapidly, like the liquid metal mercury (also named after the god) which breaks apart and reforms when touched. A mercurial person might be charming one moment and cold the next — exactly like the god who could be a helpful guide, a cunning thief, or a solemn escort of the dead.
Symbols
Fun Fact
The element mercury (quicksilver) was named after the god because of how it moves — fast, fluid, and impossible to pin down, just like Hermes.
Words We Inherited
English words and phrases that trace back to this myth. See our full guide to English words from Greek mythology.
Explore Further
Jovial
💭 conceptCheerfulness, good humour, warmth
Cheerful and good-humoured, from Jove (Jupiter/Zeus), whose planet was thought to bring happiness.
Saturnine
💭 conceptMelancholy, gloom, brooding temperament
Gloomy and slow-tempered, from Saturn (Kronos), whose distant planet was thought to cause melancholy.
Mercury
💭 conceptAstronomy and mythology
The smallest and fastest planet in the solar system, named after Mercury, the Roman messenger god identified with the Greek Hermes, because of its rapid orbital speed
God of Messengers
💭 conceptMessages, travel, boundaries, commerce, thieves
Hermes serves as divine messenger and psychopomp, escorting both words and souls between worlds.
Palladium
💭 conceptChemistry and mythology
A chemical element named after both the asteroid Pallas and the Palladium, the sacred wooden image of Pallas Athena that protected the city of Troy
Hermes Trismegistus
💭 conceptThe thrice-great, merging of Hermes and Thoth
A syncretic figure combining the Greek Hermes with the Egyptian Thoth, representing ultimate wisdom. The foundation of Hermeticism and alchemy.
Saturn
💭 conceptAstronomy and mythology
The sixth planet from the Sun, named after Saturn, the Roman god of agriculture and time identified with the Greek Titan Kronos, father of Zeus
Tantalum
💭 conceptChemistry and mythology
A chemical element named after King Tantalus of Greek mythology because of the element's tantalising inability to absorb acids, just as Tantalus could never reach the water and fruit surrounding him
Helium
💭 conceptChemistry and mythology
A chemical element named after Helios, the Greek god of the sun, because it was first detected in the solar spectrum before being found on Earth
Elysian
💭 conceptLanguage and the afterlife
An English adjective meaning blissful, heavenly, or supremely happy, derived from the Elysian Fields, the paradise in the Greek underworld reserved for heroes and the virtuous
Nemesis
💭 conceptGoddess of retribution and balance
The goddess who ensured that excessive good fortune, pride, or arrogance was balanced by corresponding misfortune. Nemesis maintained cosmic equilibrium.
Midas Touch
💭 conceptWealth, greed, unintended consequences
The ability to turn everything to profit, from King Midas who wished that all he touched would become gold.