ad-lib

基本解释

Ms. Hathaway used her hosting duties to show off herrange, singing a Broadway-style number and even cracking an ad-lib joke afterKirk Douglas’s appearance.
安妮·海瑟薇不仅利用其主持之便唱了一曲百老汇片段秀了她的音域，甚至在科克·道格拉斯出现后即兴开了一个玩笑。
People ask if a lot of it is improv or if any of it is ad-lib, which is a compliment I think, because hopefully it means that we’re pulling it off in a way that’s organic.
人们会问到是不是有很多的即兴表演或有些脱口而出的东西，我觉得其实这是种褒奖，因为这代表我们很多表演的完成都是非常自然的。
The scene in which Rose meets Jack to thank him for saving her life was improvised by the two actors at James Cameron's request, and the spitting scene was almost all ad-lib.
在詹姆斯·卡梅隆的鼓励下，Rose见Jack感谢他救了她的命那场戏是这两个演员的即兴表演，吐口水那场戏也几乎是即兴表演。

If you ad-lib something in a play or a speech, you say something that has not been planned or written beforehand.
An ad-lib is something that is said without having been planned or written beforehand.
Ad lib is also an adverb.