SPONTANEOUSLY

adv. 1. Voluntarily; of his own will or accord; used of animals; as, he acts spontaneously.
2. By its own force or energy; without the impulse of a foreign cause; used of things.
Whey turns spontaneously acid.

spontaneously

spontaneously adverb 1 they applauded spontaneously: without being asked, of one's own accord, voluntarily, on impulse, impulsively, on the spur of the moment, extempore, extemporaneously; informal off the cuff. 2 he reacted spontaneously: without thinking, automatically, mechanically, unthinkingly, involuntarily, instinctively, naturally, by oneself /itself.

spontaneously

spontaneously adverb 1 the huge crowd spontaneously broke into applause: without being asked, of one's own accord, voluntarily, on impulse, impulsively, on the spur of the moment, extempore, extemporaneously; informal off the cuff. 2 he'd reacted spontaneously, displaying the full force of his anger: without thinking, automatically, unthinkingly, involuntarily, instinctively.

spontaneously

spon t á ne ous ly 副詞 自発的に ; 自然に ; 無意識に .