ad lib

¹ American  

[ad lib, ad] / æd ˈlɪb, ˈæd /

noun

1. something improvised in speech, music, etc..

   Was that joke part of your speech or an ad lib?

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adverb

1. at one's pleasure; without restriction.

2. freely; as needed; without stint.

   Water can be given to the patients ad lib.

ad lib. ² American  

abbreviation

1. ad libitum.

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ad-lib ³ American  

[ad-lib, ad-] / ædˈlɪb, ˈæd- /

verb (used with object)

ad-libbed, ad-libbing

1. to improvise all or part of (a speech, a piece of music, etc.).

   to ad-lib one's lines.

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verb (used without object)

ad-libbed, ad-libbing

1. to act, speak, etc., without preparation.

   Throughout the play he had to ad-lib constantly.

adjective

1. impromptu; extemporaneous.

   ad-lib remarks to hecklers.

ad-lib British  

/ ædˈlɪb /

verb

1. to improvise and deliver without preparation (a speech, musical performance, etc)

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adjective

1. improvised; impromptu

adverb

1. without restraint; freely

2. music short for ad libitum

noun

1. an improvised performance, often humorous

Other Word Forms

• ad-libber noun

Etymology

Origin of ad lib¹

First recorded in 1810–20; ad libitum

Origin of ad-lib³

1915–20, v. use of ad lib

Example Sentences

"I've realised that usually I like to ad lib but you can't ad lib a script because your fellow actor doesn't know when you're going to stop talking."

From BBC • Apr. 13, 2023

Williams says working on the show was fun because of the cast chemistry, and the license to ad lib at times to make scenes funnier felt “very fulfilling.”

From Seattle Times • Jan. 27, 2023

Sure enough, after three months, the mice who ate ad lib were stricken with obesity, diabetes, liver disease, and a host of other ugly conditions.

From Salon • Oct. 9, 2022

That sequence with Mike and Eric was one of the few instances of ad libbing; Python didn’t ad lib because John didn’t like it – he’s a fundamentalist when it comes to humour, ironically.

From The Guardian • Apr. 16, 2019

There is a silence in the room and then a babble of ad lib conversation. 9TH JUROR: Please.

From "Twelve Angry Men" by Reginald Rose