It's the Word of the Day podcast for May 17th.
Today's word is mercurial, spelled M-E-R-C-U-R-I-A-L.
Mercurial is an adjective.
It's usually used to describe someone whose mood changes quickly and unpredictably.
It can also describe something that changes frequently, such as weather,
or something that is lively and quick, such as someone's wit.
Here's the word used in a sentence from the Chicago Sun-Times by Natalie Y. Moore.
The guiding light was the only radio soap to transition to TV.
Erna Phillips introduced the cliffhanger storytelling device and the mercurial female vixen character who still lives on the small screen today.
Think reality TV or a Shonda Rhimes drama.
The Roman god Mercury was the messenger and herald of the gods and also the god of merchants and thieves.
His counterpart in Greek mythology is Hermes.
His swiftness inspired the Romans to give his name to what they correctly assessed as the fastest moving planet in the solar system.
Mercury's speed also apparently made the name apt for English speakers wishing to describe those whose moods travel quickly between extremes,
a meaning mercurial has had since the mid-17th century.
The adjective mercurial comes from the Latin mercurialis, meaning of or relating to mercury.
With your Word of the Day, I'm Peter Sokolowski.
Visit Merriam-Webster.com today for definitions, wordplay, and trending word lookups.