ad lib

[ ad lib, ad ]
See synonyms for ad lib on
  1. something improvised in speech, music, etc.: Was that joke part of your speech or an ad lib?

  1. at one's pleasure; without restriction.

  2. freely; as needed; without stint: Water can be given to the patients ad lib.

Origin of ad lib

First recorded in 1810–20; see origin at ad libitum

Words Nearby ad lib

Other definitions for ad-lib (2 of 3)

[ ad-lib, ad- ]

verb (used with object),ad-libbed, ad-lib·bing.
  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-lib·bing.
  1. to act, speak, etc., without preparation: Throughout the play he had to ad-lib constantly.

  1. impromptu; extemporaneous: ad-lib remarks to hecklers.

Origin of ad-lib

1915–20, Americanism; v. use of ad lib

Other words from ad-lib

  • ad-libber, noun

Other definitions for ad lib. (3 of 3)

ad lib.

abbreviation Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use ad lib in a sentence

  • This goes on ad lib., and we were soothed to sleep by those wild yells.

  • Even here, in an embarrassing situation calling for lines spoken ad lib.

    Sundry Accounts | Irvin S. Cobb
  • Well, you look here, my bloke: I'll have fizz ad lib., or it won't wash.

    The Ebb-Tide | Robert Louis Stevenson and Lloyde Osbourne
  • "I needed a job awful bad," I answered sullenly, knowing it sounded like an ad lib.

    The Old Die Rich | Horace Leonard Gold

British Dictionary definitions for ad-lib


/ (ædˈlɪb) /

verb-libs, -libbing or -libbed
  1. to improvise and deliver without preparation (a speech, musical performance, etc)

adjective(ad lib when predicative)
  1. improvised; impromptu

adverbad lib
  1. without restraint; freely

  2. music short for ad libitum

  1. an improvised performance, often humorous

Origin of ad-lib

C18: short for Latin ad libitum, literally: according to pleasure

Derived forms of ad-lib

  • ad-libber, noun

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