- Today's Word
Mercurial
mər-KYUR-ee-uhl (or mur-KYOOR-ee-uhl)
Definition
- (adjective) Subject to sudden or unpredictable changes of mood or mind; volatile, capricious.
- Relating to the Roman god Mercury (or the planet Mercury), often implying qualities of cleverness, eloquence, or swiftness.
Example
Her mercurial temperament made her both exhilarating and exhausting to work with; one moment she was full of boundless enthusiasm, and the next, stormy and withdrawn.
Fun Fact
The word “mercurial” is derived from the Roman god Mercury, who was known for his speed, wit, and trickery. Mercury was also the messenger of the gods, and his unpredictable nature made him a fitting inspiration for the term. In alchemy, “mercurial” also refers to mercury (quicksilver), a liquid metal known for its fluid and volatile properties, reinforcing the word’s association with changeability. Over time, “mercurial” evolved to describe not only physical but also emotional and mental shifts, making it a vivid way to characterize people with ever-changing moods.
(adjective) Too great, extreme, or overwhelming to be adequately expressed in words.
Standing at the edge of the Grand Canyon for the first time, she was struck by an ineffable feeling — something vast and wordless that no photograph or description had ever come close to capturing.
Ineffable derives from the Latin ineffabilis — “unutterable” — built from in- (“not”) and effabilis (“speakable”), itself from effari, meaning “to speak out,” from ex- (“out”) and fari (“to speak”). It entered English in the 15th century, used predominantly in religious and mystical contexts to describe the divine — God being the ultimate ineffable subject, a presence so vast that language itself collapses in the attempt to contain it.