spon·​ta·​ne·​ous spän-ˈtā-nē-əs How to pronounce spontaneous (audio)
: proceeding from natural feeling or native tendency without external constraint
: arising from a momentary impulse
: controlled and directed internally : self-acting
spontaneous movement characteristic of living things
: produced without being planted or without human labor : indigenous
: developing or occurring without apparent external influence, force, cause, or treatment
: not apparently contrived or manipulated : natural
spontaneously adverb
spontaneousness noun

Did you know?

When English philosopher Thomas Hobbes penned his 1656 The Questions Concerning Liberty, Necessity, and Chance he included the following: "all voluntary actions … are called also spontaneous, and said to be done by man's own accord." Hobbes was writing in English, but he knew Latin perfectly well too, including the source of spontaneous; the word comes, via Late Latin spontaneus, from the Latin sponte, meaning "of one's free will, voluntarily." In modern use, the word spontaneous is frequently heard in more mundane settings, where it often describes what is done or said without a lot of thought or planning.

Choose the Right Synonym for spontaneous

spontaneous, impulsive, instinctive, automatic, mechanical mean acting or activated without deliberation.

spontaneous implies lack of prompting and connotes naturalness.

a spontaneous burst of applause

impulsive implies acting under stress of emotion or spirit of the moment.

impulsive acts of violence

instinctive stresses action involving neither judgment nor will.

blinking is an instinctive reaction

automatic implies action engaging neither the mind nor the emotions and connotes a predictable response.

his denial was automatic

mechanical stresses the lifeless, often perfunctory character of the response.

a mechanical teaching method

Examples of spontaneous in a Sentence

Shane has a lovely habit of paying us spontaneous visits: one time she brought over a jar of a pickle she'd recently put up; another time just a good story or two. James Oseland, Saveur, December 2006
Cold viruses can damage the olfactory system directly. This loss of smell may last even after the cold is over. Sometimes the sense comes back as suddenly as it disappeared, perhaps because even as adults we generate new olfactory neurons. Spontaneous improvement might be a person's best hope, because there are no real proven treatments for reversing olfactory nerve damage. Harvard Health Letter, September 2001
Peter Jakobsen of the European Space Agency, which built the Faint Object Camera, drew spontaneous applause at the January meeting when he showed an image of supernova SN1987A from the instrument. Kristin Leutwyler, Scientific American, March 1994
The comment was completely spontaneous. He's a guy who's spontaneous and fun.
Recent Examples on the Web The push was a spontaneous act of self-defense, Brian said. Eli Saslow Erin Schaff, New York Times, 19 Nov. 2023 The third vector is seeing people use Roblox more frequently for spontaneous connection on top of the half-hour to one-hour type gameplay. Phil Wahba, Fortune, 15 Nov. 2023 The series will bring notable figures together for 20 fun and spontaneous half-hour episodes. Okla Jones, Essence, 15 Nov. 2023 In the absence of a live broadcast, will there be opportunities for spontaneous moments that often arise at awards shows? Paul Grein, Billboard, 3 Nov. 2023 Think of puff pastry’s flaky confetti as spontaneous party decor. Alex Beggs, Bon Appétit, 9 Nov. 2023 While doctors currently don't have ways to prevent spontaneous fainting spells, Augustine said targeting the neurons identified in his study could be one approach. Aria Bendix, NBC News, 3 Nov. 2023 Riley contended that the program is geared towards spontaneous travelers who likely wouldn’t use a specialist in the first place. Charlie Hobbs, Condé Nast Traveler, 3 Nov. 2023 Revolutions are often imagined as spontaneous popular upheavals, but these uprisings began with local elites dissatisfied with centralized control. Maurizio Isabella, Foreign Affairs, 24 Oct. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'spontaneous.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Late Latin spontāneus "voluntary, unconstrained" (from Latin sponte "of one's own accord, by one's own agency," ablative of *spons —of uncertain origin— + -āneus, suffix forming adjectives from temporal adverbs, from -ānus -an entry 2 + -eus -eous) + -ous

Note: The suffix -āneus, a joining of -ānus and -eus, occurs earlier with compound verbs (as consentāneus "agreeable, consentaneous," succīdāneus "killed as a substitute or addition"—see succedaneum) and phrasal derivatives (as circumforāneus "itinerant," mediterrāneus "remote from the coast, inland"). The earliest derivatives from temporal adverbs are subitāneus "happening without warning, sudden" (Seneca) and praesentāneus "immediately operative, prompt in effect" (in Seneca and Pliny).

First Known Use

1605, in the meaning defined at sense 1

Time Traveler
The first known use of spontaneous was in 1605


Dictionary Entries Near spontaneous

Cite this Entry

“Spontaneous.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/spontaneous. Accessed 6 Dec. 2023.

Kids Definition


spon·​ta·​ne·​ous spän-ˈtā-nē-əs How to pronounce spontaneous (audio)
: done, said, or produced freely and naturally
spontaneous laughter
: acting or taking place without any outside force or cause
spontaneously adverb
spontaneousness noun

Medical Definition


spon·​ta·​ne·​ous spän-ˈtā-nē-əs How to pronounce spontaneous (audio)
: proceeding from natural feeling or native tendency without external constraint
: developing without apparent external influence, force, cause, or treatment
a spontaneous nosebleed
spontaneously adverb

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