spontaneous

spontaneous
    adj 1: happening or arising without apparent external cause;
           "spontaneous laughter"; "spontaneous combustion"; "a
           spontaneous abortion" [syn: {spontaneous}, {self-
           generated}] [ant: {induced}]
    2: said or done without having been planned or written in
       advance; "he made a few ad-lib remarks" [syn: {ad-lib},
       {spontaneous}, {unwritten}]
    

Spontaneous \Spon*ta"ne*ous\ (sp[o^]n*t[=a]"n[-e]*[u^]s), a. [L.
   spontaneus, fr. sponte of free will, voluntarily.]
   1. Proceeding from natural feeling, temperament, or
      disposition, or from a native internal proneness,
      readiness, or tendency, without constraint; as, a
      spontaneous gift or proposition.
      [1913 Webster]

   2. Proceeding from, or acting by, internal impulse, energy,
      or natural law, without external force; as, spontaneous
      motion; spontaneous growth.
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   3. Produced without being planted, or without human labor;
      as, a spontaneous growth of wood.
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   {Spontaneous combustion}, combustion produced in a substance
      by the evolution of heat through the chemical action of
      its own elements; as, the spontaneous combustion of waste
      matter saturated with oil.

   {Spontaneous generation}. (Biol.) See under {Generation}.
      [1913 Webster]

   Syn: Voluntary; uncompelled; willing.

   Usage: {Spontaneous}, {Voluntary}. What is voluntary is the
          result of a volition, or act of choice; it therefore
          implies some degree of consideration, and may be the
          result of mere reason without excited feeling. What is
          spontaneous springs wholly from feeling, or a sudden
          impulse which admits of no reflection; as, a
          spontaneous burst of applause. Hence, the term is also
          applied to things inanimate when they are produced
          without the determinate purpose or care of man.
          "Abstinence which is but voluntary fasting, and . . .
          exercise which is but voluntary labor." --J. Seed.
          [1913 Webster]

                Spontaneous joys, where nature has its play,
                The soul adopts, and owns their firstborn away.
                                                  --Goldsmith.
          [1913 Webster] -- {Spon*ta"ne*ous*ly}, adv. --
          {Spon*ta"ne*ous*ness}, n.
          [1913 Webster]
    

119 Moby Thesaurus words for "spontaneous":
      ad lib, arbitrary, automated, automatic, automatous, autonomous,
      bat, baton, billy, billy club, bludgeon, casual, club, cybernated,
      discretional, discretionary, elective, extemporaneous, extempore,
      free, free will, gratuitous, gut, ill-advised, ill-considered,
      ill-devised, immediate, impetuous, impromptu, improvised,
      impulsive, inadvertent, indeliberate, independent, inherent,
      innate, instinctive, instinctual, involuntary, libidinal, mace,
      mechanical, natural, nightstick, nonmandatory, off the cuff,
      offered, offhand, optional, proffered, reflex, reflexive,
      self-acting, self-active, self-adjusting, self-closing,
      self-controlled, self-cooking, self-determined, self-determining,
      self-directed, self-directing, self-dumping, self-governed,
      self-governing, self-lighting, self-operative, self-regulative,
      self-starting, self-winding, self-working, semiautomatic, simple,
      snap, spontoon, spur-of-the-moment, subliminal, truncheon,
      unadvised, unannounced, unasked, unbesought, unbidden,
      uncalculated, uncalled-for, uncoerced, uncompelled, unconscious,
      unconsidered, unconstrained, undeliberate, undeliberated,
      undesigned, unforced, unguarded, uninfluenced, unintended,
      unintentional, uninvited, unlearned, unmeditated, unplanned,
      unpremeditated, unprepared, unpressured, unprompted, unrehearsed,
      unrequested, unrequired, unsolicited, unsophisticated, unsought,
      unstudied, unthinking, unwilled, unwitting, voluntary, volunteer,
      willful