ad libitum Ad Li-BEE-tum Your browser does not support the audio element. [ Latin , at liberty ] Definition At the discretion of the performer; At pleasure, changing the tempo of a particular passage. A part that may be omitted if desired. It is often used in the shortened form, ad lib or Ad l. More about tempo-terminology. See Also [Abbreviation] ad lib [Abbreviation] Ad l. [Italian] a piacere Share Share on Facebook (opens in a new tab) Share on X (opens in a new tab) Last Updated: 2013-03-05 21:46:51