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, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.