spontaneous

The definition of spontaneous is unplanned or done on impulse.

(adjective)

An example of spontaneous is waking up and deciding to take a trip across the country that day.

See spontaneous in Webster's New World College Dictionary

adjective

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: LL spontaneus < L sponte, of free will < IE base *(s)pen(d)-, to pull > spin

Related Forms:

See spontaneous in American Heritage Dictionary 4

adjective

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:

Origin: From Late Latin spontāneus, of one's own accord

Origin: , from Latin sponte; see (s)pen- in Indo-European roots

Related Forms: