An ad lib is words spoken without preparation. Throw in an ad lib.
The best ones are prepared in advance, which every performer admits eventually. An ad lib that lands is remembered longer than anything in the script.
1nounad libWords spoken without preparation.
“The ad lib got the biggest laugh of the night.”
ad lib is a remark.
Short for the Latin ad libitum, at pleasure, which in music means play this freely.
New Latin
ad libitum
English, today
ad lib
Abbreviation of ad libitum, borrowed from New Latin ad libitum.
Etymology from Wiktionary, CC BY-SA