an offhand remark.What is unrehearsed is said or done without rehearsal or practice though not necessarily without forethought 随意的评论。所谓unrehearsed，就是未经复述或练习就说或做的，虽然没有不构思的必要收藏
Skilled at or given to unrehearsed speech or performance 擅长于或倾向于即兴演说或即兴表演的.收藏
形容词解释：