Definition of: spontaneous

(spon·tā′nē·əs) adjective
1. Arising from inherent qualities or tendencies without external efficient cause; done or acting from one's own impulse, prompting, or desire.
2. Not having material causation outside itself.
3. Generated or produced without human labor; wild or sporadic; indigenous.
4. Biol. Apparently arising independently of external stimulus, influence, or conditions. [<LL spontaneus <L sponte of free will]
—spon·ta′ne·ous·ly adverb
—spon·ta′ne·ous·ness noun Synonyms: automatic, instinctive, involuntary, unbidden, voluntary, willing. That is spontaneous which is freely done, with no external compulsion and, in human actions, without special premeditation or distinct determination of the will; that is voluntary which is freely done with distinct act of will; that is involuntary which is independent of the will, and perhaps in opposition to it; a willing act is not only in accordance with will, but with desire. Thus voluntary and involuntary, which are antonyms of each other, are both partial synonyms of spontaneous. An infant's smile in answer to that of its mother is spontaneous; the smile of a pouting child wheedled into good humor is involuntary. In physiology the action of the heart and lungs is involuntary action; the growth of the hair and nails is spontaneous; the action of swallowing is voluntary up to a certain point, beyond which it becomes involuntary or automalic.