• WordNet 3.6
    • adj spontaneous said or done without having been planned or written in advance "he made a few ad-lib remarks"
    • adj spontaneous happening or arising without apparent external cause "spontaneous laughter","spontaneous combustion","a spontaneous abortion"
    • ***
Webster's Revised Unabridged Dictionary
    • Spontaneous Proceeding from natural feeling, temperament, or disposition, or from a native internal proneness, readiness, or tendency, without constraint; as, a spontaneous gift or proposition.
    • Spontaneous Proceeding from, or acting by, internal impulse, energy, or natural law, without external force; as, spontaneous motion; spontaneous growth.
    • Spontaneous Produced without being planted, or without human labor; as, a spontaneous growth of wood.
    • ***
Century Dictionary and Cyclopedia
    • spontaneous Proceeding from a conscious or unconscious internal impulse; occurring or done without the intervention of external causes; in a restricted sense, springing from one's own desire or volition, apart from any external suggestion or incitement. Of late the employment of spontaneous in the sense of ‘irreflective’ or ‘not controlled by a definite purpose’ is creeping in from the French; but this is an objectionable use of the term.
    • spontaneous Growing naturally, without previous human care.
    • spontaneous Growing as native; indigenous.
    • spontaneous In biology, instinctive or automatic, as some actions of animals which depend upon no external stimulus and are performed without apparent motive or purpose; uninfluenced by external conditions, as a change in structural character. Compare spontaneity, 2. Spontaneous actions may be either voluntary, in a usual sense, as the gambols of puppies or kittens, or involuntary and quite uncontrollable by the will. Of the latter class, some are abnormal, as spontaneous (in distinction from induced) somnambulism, and these are also called idiopathic.
    • spontaneous Synonyms Willing, etc. (see voluntary), instinctive, unbidden.
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Chambers's Twentieth Century Dictionary
    • adj Spontaneous spon-tā′nē-us of one's free-will: involuntary: acting by its own impulse or natural law: produced of itself or without interference
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  • Henri Frederic Amiel
    “Analysis kills spontaneity. The grain once ground into flour springs and germinates no more.”
  • Daniel J. Boorstin
    “The world of crime is a last refuge of the authentic, uncorrupted, spontaneous event.”
  • Reggie Leach
    Reggie Leach
    “Success is not the result of spontaneous combustion, you must set yourself on fire first.”
  • Sidonie Gabrielle Colette
    “My true friends have always given me that supreme proof of devotion, a spontaneous aversion for the man I loved.”
  • Henry Miller
    “All growth is a leap in the dark, a spontaneous, unpremeditated act without benefit of experience.”
  • Mark Caine
    Mark Caine
    “Meticulous planning will enable everything a man does to appear spontaneous.”


Webster's Revised Unabridged Dictionary
L. spontaneus, fr. sponte, of free will, voluntarily
Chambers's Twentieth Century Dictionary
L. spontaneussponte, of one's own accord.


In literature:

We have already alluded to the spontaneity and universality of these organizations at the beginning of the war.
"Woman's Work in the Civil War" by Linus Pierpont Brockett
From this time my tongue was, as it were, loosened, and I spoke spontaneously and without effort.
"Apologia Pro Vita Sua" by John Henry Cardinal Newman
By a free agent is understood an agent that is able to act without restraint, or spontaneously.
"Mind and Motion and Monism" by George John Romanes
Hence every Menorah Society is the result of a spontaneous desire among students to organize for Menorah purposes.
"The Menorah Journal, Volume 1, 1915" by Various
Our businesses and professions cannot be conducted on the spontaneous promptings of instinct.
"Human Traits and their Social Significance" by Irwin Edman
To very intimate friends, however, the spontaneous note of thanks would be more courteous.
"The Etiquette of To-day" by Edith B. Ordway
Numerous experiments have led to the conclusion that this is also the cause for spontaneous combustion.
"Steam, Its Generation and Use" by Babcock & Wilcox Co.
Nothing must restrain the spontaneity of the human mind.
"Socialism" by John Spargo
It grows spontaneously on deep, sandy soils, when once naturalized.
"Cattle and Their Diseases" by Robert Jennings
Note the spontaneous imitation.
"The Ontario High School Reader" by A.E. Marty

In poetry:

The sigh spontaneous rose, the tear
Involuntarily flow'd;
No word of comfort could she speak,
Nor would she weep aloud.
"A Tale" by John Logan
She has a world of ready wealth,
Our minds and hearts to bless—
Spontaneous wisdom breathed by health,
Truth breathed by cheerfulness.
"The Tables Turned" by William Wordsworth
With active zeal, which no cold medium knew,
Nor party ruled, nor prejudice confined,
But, to thy heart's spontaneous impulse true,
Thou gay'st thy country ALL thy mighty mind.
"Sheridan" by Thomas Gent
I envied that bird, on that fair summer morning,
When nature lay decked with spontaneous art,
As he circled, with aspect defiant and scorning,
And perched on a pinnacle's loftiest part.
"Suggested" by Alfred Castner King
In the action of naturalness
The Ten Virtues spontaneously grow;
All the Ten Vices are thus purified.
By corrections or remedies
The Illuminating Void is ne'er disturbed.
These are the Key-points of Action.
"The Song Of View, Practice, And Action" by Jetsun Milarepa
So, sown in little clumps about the world,
The fair, the faithful and the uncondemned
Broke out spontaneously all over time,
Setting against the random facts of death
A ground and possibility of order,
Against defeat the certainty of love.
"Kairos and Logos" by W H Auden

In news:

Comparisons are made to "the spontaneous flair of classic Blue Note recordings".
Rice, Benghazi and spontaneity .
Investigators said spontaneous combustion started the fire at Nirchi's Pizza on the Vestal Parkway in Vestal.
The creation of the universe was spontaneous and can all be explained by science.
CIA told Susan Rice Benghazi ' spontaneously inspired'.
Ever feel like you aren't spontaneous or courageous enough.
The seniors spontaneously belt out the tune while at a Target in Kansas.
Those glass doors in your shower can spontaneously explode, causing injuries and a big cleanup to boot.
If your four-year-old granddaughter dances spontaneously to the opener of a recording, something is right about it.
Shane Told likes to be spontaneous.
Give Spontaneous Construction Building Contest a Try.
Google Apps Sparks Spontaneous Innovation.
Enjoy a ' Spontaneous ' night out.
Since Kat Koppett developed the improv show Spontaneous Broadway in the mid-1990s, it has been performed around the world.
"It's about people making music spontaneously in public space," she said.

In science:

The interference experiments with single photons mentioned in Sec. 4.3 have been performed with photon pairs generated in spontaneous parametric downconversion [127].
Quantum Physics of Simple Optical Instruments
Finally, we explain briefly how the singlet state (6.18) is generated in spontaneous parametric downconversion [127].
Quantum Physics of Simple Optical Instruments
Bell state (6.18) in the regime of spontaneous parametric downconversion.
Quantum Physics of Simple Optical Instruments
The dominant noise in our CPF gate arises from photon loss due to atomic spontaneous emission, leading to a vacuum-state output when the input is a single-photon pulse.
Scalable photonic quantum computation through cavity-assisted interaction
Fig. 2c shows the probability Ps of spontaneous emission loss as a function of g/κ for the input state |1i ⊗ |hi, assuming γs = κ.
Scalable photonic quantum computation through cavity-assisted interaction