spontaneous
/spɒnˈteɪnɪəs/adjective
1- performed or occurring as a result of a sudden inner impulse or inclination and without premeditation or external stimulus自发的, 不由自主的：
the audience broke into spontaneous applause
观众们情不自禁地热烈鼓掌
a spontaneous display of affection.
爱意的自然流露。
1.1
- (of a person) having an open, natural, and uninhibited manner（人）天真率直的。
1.2
- (of a process or event) occurring without apparent external cause（程序, 事件）自发的, 自然的：
spontaneous miscarriages.
自然流产。
1.3
- archaic (of a plant) growing naturally and without being tended or cultivated〈古〉（植物）自生的, 野生的, 非人工栽培的。
1.4
- Biology (of movement or activity in an organism) instinctive or involuntary【生】（机体活动）本能的; 自发的：
the spontaneous mechanical activity of circular smooth muscle.
环状平滑肌的自然机械活动。
派生词
spontaneity
nounspontaneously
adverb词源
mid 17th cent.: from late Latin spontaneus （from (sua) sponte 'of （one's） own accord'） + -OUS.