1969, American English, shortening of liberation, used with possessives, originally in Women's Lib. Colloquial shortening libber for liberationist is attested from 1971.
权威例句
1. I spoke from the pulpit ad lib.
我在讲坛上发表即兴演说。
2. I voted Lib Dem.
我投了自由民主党的票。
3. I lost my notes and had to ad - lib the whole speech.
我把讲稿丢了,只好临时说了一通.
4. Throughout the plan she had to ad - lib constantly.