- The definition of spontaneous is unplanned or done on impulse.
An example of spontaneous is waking up and deciding to take a trip across the country that day.
spontaneous definition by Webster's New World
- acting in accordance with or resulting from a natural feeling, impulse, or tendency, without any constraint, effort, or premeditation
- having no apparent external cause or influence; occurring or produced by its own energy, force, etc. or through internal causes; self-acting
- growing naturally without being planted or tended; indigenous; wild
Origin: Late Latin spontaneus ; from Classical Latin sponte, of free will ; from Indo-European base an unverified form (s)pen(d)-, to pull from source spin
spontaneous definition by American Heritage Dictionary
- Happening or arising without apparent external cause; self-generated.
- Arising from a natural inclination or impulse and not from external incitement or constraint.
- Unconstrained and unstudied in manner or behavior.
- Growing without cultivation or human labor.
Origin: From Late Latin spontāneus, of one's own accord, from Latin sponte; see (s)pen- in Indo-European roots.
- spon·taˈne·ous·ly adverb
- spon·taˈne·ous·ness noun