Definition of spontaneous in US English:



  • 1Performed or occurring as a result of a sudden inner impulse or inclination and without premeditation or external stimulus.

    ‘the audience broke into spontaneous applause’
    ‘a spontaneous display of affection’
    • ‘His editorial vision was flawless, spontaneous and always laser-sharp.’
    • ‘Actors, particularly, responded to his approach, claiming this method gave a fresh, spontaneous quality to their performances.’
    • ‘On a day's journey off the beaten track one might meet very few people, but their hospitality was spontaneous and generous.’
    • ‘Let me expound upon a few spontaneous thoughts.’
    • ‘The spontaneous applause at this moment in the work from the audience attested to its impact!’
    • ‘On a surface read, what appears to be unscripted, spontaneous, and endlessly eventful is not.’
    • ‘Their first scene received well-deserved spontaneous applause from the packed audience.’
    • ‘The film did indeed cause several bouts of spontaneous applause during the screening I saw.’
    • ‘For the second time in the festival, the crowd broke into spontaneous cheers and applause as the village women stood up against the oppressive regime of their village.’
    • ‘The 27-year-old director also exhibits a great reverence for his actors, whose performances often seem so spontaneous, many viewers mistakenly believe the film was improvised.’
    • ‘Now, it's more concentrated and not as spontaneous.’
    • ‘This results in a show that is all spontaneous energy, time and time again.’
    • ‘They just do it, and it's beautiful and creative and spontaneous.’
    • ‘She's so lively and smiley that her responses to the audience seem entirely unforced and spontaneous.’
    • ‘The performer must make spontaneous decisions about what pose to strike and where to freeze the action.’
    • ‘A lot of it has a spontaneous feel and that's why it's so good.’
    • ‘This was unfamiliar music to them, and to show such a spontaneous reaction was very gratifying.’
    • ‘The audience loved it so much that they gave spontaneous applause after the fierce ending of the first movement.’
    • ‘The audience alternated compulsive chatter with breathless silence, and there were three or four mid-film bouts of spontaneous, delighted applause.’
    • ‘Typically we do most of our grocery shopping at large supermarkets, and do only impromptu, spontaneous purchases from convenience stores and gas marts.’
    unforced, voluntary, unconstrained, unprompted, unbidden, unsolicited, unplanned, unpremeditated, unrehearsed, impulsive, impetuous, unstudied, impromptu, spur-of-the-moment, extempore, extemporaneous
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    1. 1.1 (of a person) having an open, natural, and uninhibited manner.
      • ‘Both improvisation and the musical hold the contradictory idea that spontaneous performance is available to all and that some people are more spontaneous or open than others.’
      • ‘His natural ability to be flexible and spontaneous at the same time always commended itself to orchestras, but I don't believe he looked on himself as a stylist.’
      • ‘Sarah is the free spirit black sheep of a rich family who is known for her impulsive, spontaneous personality.’
      • ‘Whistler's charm was genuine and completely spontaneous.’
      • ‘Everything from Finny's appearance to his walk to his personality is natural and spontaneous.’
      • ‘I have never been spontaneous, but people change.’
      • ‘You need to be spontaneous and to be able to react to any given situation, because no group of children are the same.’
      • ‘Apart from this I try to be spontaneous, like the sudden ideas one gets during good conversations.’
      natural, uninhibited, relaxed, unselfconscious, unaffected, easy, free and easy
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    2. 1.2 (of a process or event) occurring without apparent external cause.
      ‘spontaneous miscarriages’
      • ‘Some spontaneous abortions, apparently, ‘can be seen as a woman's reproductive organs unconsciously deciding not to go ahead with this pregnancy’.’
      • ‘I guess it's something like spontaneous human combustion, only different.’
      • ‘The spontaneous form of Creutzfeldt-Jakob disease, the one not linked to consumption of beef or anything else, claimed over 1,000 Brits in the same time period.’
    3. 1.3Biology (of movement or activity in an organism) instinctive or involuntary.
      ‘the spontaneous mechanical activity of circular smooth muscle’
      • ‘For what it's worth, a zooid is ‘an organic cell capable of spontaneous movement independent of the parent organism.’’
      reflex, automatic, knee-jerk, involuntary, unthinking, unconscious, instinctive, instinctual
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    4. 1.4archaic (of a plant) growing naturally and without being tended or cultivated.


Mid 17th century: from late Latin spontaneus (from ( sua) sponte ‘of (one's) own accord’) + -ous.