ad lib·i·tum (ăd lĭbĭ-təm)
1. Music At the discretion of the performer. Used chiefly as a direction giving license to alter or omit a part.
2. Of or relating to a diet in which the amount of food is not restricted.
1. Music At the discretion of the performer: repeat ad libitum.
2. Without restriction; freely: mice that were fed ad libitum.
[Latin ad, according to + libitum, past participle of libēre, to please.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.