extemporary

adj.无准备的,随口说的

即兴的；即兴演讲的；

形容词；

1、I was impressed by his extemporary speech at the conference.
我对他在会议上的即兴演讲印象深刻。
2、She is known for her extemporary wit and humor.
她以她的即兴机智和幽默而闻名。