Free choice; allowing cattle to eat all they want.

Often shortened to ad lib; term used to refer to the amount of feed ingested when made completely available without limitation or restriction.

In accordance with desire.

Ad Libitum is a Latin term which means “at pleasure” or at the discretion of the performer. The term is generally used as a direction imparting license to alter or omit a part. The term ad libitum is [..]

(ad lib.) at choice; freely 1) A passage may be performed freely. 2) An instrument in a score may be omitted.

at the performer's liberty

 (commonly ad lib; Latin) – at liberty; i.e., the speed and manner of execution are left to the performer

at pleasure, quite freely

At liberty; the performer decides how to sing or play the respective section or notes

At choice, such as indicating whether an instrument is used

at the pleasure of the performer. Usually it is used to indicate that a part of a piece may be omitted (in a piece with several instruments or voices) or it can indicate that the performer can “improv [..]

(music) at one's pleasure, allowing freedom to improvise, allowing variation from the printed notes or tempo. Without advanced preparation; spontaneously; impromptu; ad lib. Without restriction. [..]