spontaneous

 
Pronunciation: /spɒnˈteɪnɪəs/

adjective

  • performed or occurring as a result of a sudden impulse or inclination and without premeditation or external stimulus: the audience broke into spontaneous applause a spontaneous display of affection
  • having an open, natural, and uninhibited manner.
  • (of a process or event) occurring without apparent external cause: spontaneous miscarriages
  • Biology (of movement or activity in an organism) instinctive or involuntary: the spontaneous mechanical activity of circular smooth muscle
  • archaic (of a plant) growing naturally and without being tended or cultivated.

Derivatives

spontaneously

adverb

Origin:

mid 17th century: from late Latin spontaneus (from (sua) sponte 'of (one's) own accord') + -ous

Spelling help

Remember that spontaneous ends with -neous.