好词典
spontaneously
UK //spɒnˈteɪniəsli//US //spɑːnˈteɪniəsli//
词源
源自拉丁语 'spontaneus'（自愿的）+ 后缀 '-ly'，17世纪进入英语。
adverb
❶ 指行为或事件未经事先计划或准备，自然发生或突然产生，强调即兴和无预谋的特点。
“The crowd spontaneously started singing the national anthem.”
（人群自发地开始唱国歌。）
“She spontaneously decided to take a trip to the beach.”
（她一时兴起决定去海滩旅行。）
同义词:impulsively, unplanned, naturally, freely, voluntarily
常见短语
act spontaneously — 指不经过深思熟虑或计划，凭直觉或一时冲动采取行动。
“Children often act spontaneously without thinking about the consequences.”
（孩子们常常不考虑后果就凭直觉行动。）