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Showing results for ad lib. Search instead for ad-libbed.
Synonyms

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?

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.

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.

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)

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

adjective

  1. improvised; impromptu

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

adverb

  1. without restraint; freely

  2. music short for ad libitum

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

noun

  1. an improvised performance, often humorous

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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

Vocabulary lists containing ad-lib

Reading: Literature - Drama - Introductory

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Theater - Introductory

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Reading: Literature - Drama - Middle School

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

“It’s a spill-your-guts-out record,” she says, adding that for every song, she’d write a first verse, then ad lib the rest in the studio.

From Los Angeles Times • Aug. 6, 2025

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

We shoot six episodes a day and they just fly along because it’s all ad lib.

From Seattle Times • Sep. 13, 2021

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

So the next day I go to Room 402 at lunch and do my best to volley back right answers to Rosa’s ad lib math problems.

From "The Running Dream" by Wendelin Van Draanen

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.