1.自发的，无意识的 done, happening, said, etc. because of a voluntary impulse from within, not caused or suggested by sb/sth outside 2.自然的，天真率直的 natural, not forced
词汇搭配
～+名词
～ applause自发的鼓掌 ～ gaiety of manner天真愉快的神态
句型例句
用作定语
▲ ～+n.
Her successful jump brought a spontaneous cheer from the crowd.她成功越过横竿后，观众立即发出一阵欢呼声。
用作表语
▲ S+be+～
The eruption of a volcano is spontaneous.火山的爆发是自发的。