spontaneous/spɑnˋtenIəs; spɒnˈteIniəs/adj something that is spontaneous happens without being planned 自发的﹔一时冲动的﹐兴之所至的: a spontaneous reaction 本能反应spontaneous applause 自发的鼓掌 —spontaneously adv —spontaneity /͵spɑntəˋniətI; ˌspɒntəˈniːəti or ˌspɒntəˈniːIti/n [U]