adjective1 : done, said, or produced freely and naturally 2 : arising from a momentary impulse 3 : produced without being planted or without human labor : indigenous 4 : acting or taking place without apparent external cause or influence
Since childhood, Marie has been prone to spontaneous displays of affection.
“Surveys show that visitors and New Yorkers aren’t looking for Disneyland when they go to Times Square, which they want to remain spontaneous and a little crazy.” — Michael Kimmelman, The New York Times, 22 Aug. 2015
Did you know?
Spontaneous derives, via the Late Latin spontaneus, from the Latin sponte, meaning “of one’s free will, voluntarily,” and first appeared in English in the mid-17th century. Thomas Hobbes was an early adopter: he wrote that “all voluntary actions … are called also spontaneous, and said to be done by man’s own accord” in his famous 1656 The Questions Concerning Liberty, Necessity, and Chance. Today the word is more often applied to things done or said in a natural and often sudden way, without a lot of thought or planning—or to people who do or say things in such a way.