详细解释:n. 即席演出, 即兴曲
a. 即席的
ad. 即席
英语解释：
名词 impromptu:
an extemporaneous speech or remarka short musical passage that seems to have been made spontaneously without advance preparation形容词 impromptu:
with little or no preparation or forethought同义词：ad-lib, extemporaneous, extemporary, extempore, offhand, offhanded, off-the-cuff, unrehearsed