Mercurial (adj)
mur-ku-ree-al
Subject to sudden or unpredictable changes of mood or mind.
Of or containing the element mercury.
Late Middle English (in mercurial (sense 3 of the adjective)): from Latin mercurialis ‘relating to the god Mercury’, from Mercurius ‘Mercury’. mercurial (sense 1 of the adjective) dates from the mid 17th century.
Example sentences
“I was used to her mercurial moods!”
