ad-lib
verb [intransitive, transitive]to say something in a speech or a performance that you have not prepared or practised synonym improvise即席講話;即興表演 She abandoned her script and began ad-libbing. 她抛開腳本即興表演起來。 - ad-lib something
I lost my notes and had to ad-lib the whole speech. 我把講稿弄丢了,只好臨時說了一通。 He ad-libbed his way through the meeting. 他在會議中即興發揮。
Word Originearly 19th cent. (as an adverb): abbreviation of ad libitum.