improvise

v. 即席写作,即席即兴,即席而作

As we've not got the proper materials, we'll just have to improvise.

我们没有弄到合适的材料, 只好临时凑合了.

The pianist forgot his music and had to improvise (the accompaniment).

弹钢琴的人把乐谱忘了, 只好即兴伴奏.