1. The act of regulating or the state of being regulated.
2. A principle, rule, or law designed to control or govern conduct.
3. A governmental order having the force of law. Also called executive order.
4. Embryology The capacity of an embryo to continue normal development following injury to or alteration of a structure.
5. Sports The standard playing period for a timed game, prior to overtime or a shootout.
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.