及物/不及物动词即兴演出; 当场作出; 口随口说出（俏皮话）; 无准备地说（或做）

形容词即兴的; 即席发言的; 临时插入的; 当场作出的

副词口临时插入地; 随便地; 任意地; 当场

名词主美临时插入的台词（或动作），即兴的音乐，即席的发言（或评论）

1. 即兴演出，临时插入（脚本或讲稿中没有的台词）
If you ad-lib something in a play or a speech, you say something which has not been planned or written beforehand.

e.g. He began comically ad-libbing a script...
他即兴调侃起了一段剧本。
e.g. He's good at ad-libbing his way out of trouble...
他善于为自己妙语解围。

2. 即兴（或临时插入）的台词
An ad-lib is something which is said without having been planned or written beforehand.

e.g. Every time I fluffed a line Lenny got me out of trouble with a brilliant ad-lib.
每次我台词出错时，伦尼都通过机智的临场发挥帮我解围。

1. 七彩网.英语单词

noun

1. remark made spontaneously without prior preparation

e.g. his ad-libs got him in trouble with the politicians