extempore
adjective, adverb formal uk/ekˈstem.pər.i/ us/ekˈstem.pər.i/
即兴的（地）;无准备的（地）;临场的（地）
done or said without any preparation or thought
an extempore performance 即兴表演
At the audition, the actors were asked to perform extempore. 试镜时，要求演员们作即兴表演。
Synonyms: extemporaneous impromptu