In the Soliloquy lexicon
mercurial
Subject to sudden and unpredictable changes of mood or mind; lively and volatile.
Used in a sentence
Her mercurial temperament made each meeting unpredictable.
Where it comes from
From Latin mercurialis ‘of Mercury’, from Mercurius, the Roman god associated with the swift, changeable planet Mercury.
Its journey
Born in Latin as mercurialis, “of Mercury”, it named the Roman god—and, by extension, the planet and the quick, gleaming metal quicksilver. Passing through medieval Latin into English in the fourteenth century, it first meant simply “relating to Mercury”. Astrological belief then made the god’s swift, restless influence a human temperament: lively, ingenious, and by the seventeenth century, unpredictably changeable.
Nearby words
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