1. 1. The act of establishing official rules, laws, or directions.
   2. Something prescribed as a rule.
2. 1. A written order, especially by a physician, for the preparation and administration of a medicine or other treatment.
   2. A prescribed medicine or other treatment.
   3. An ophthalmologist's or optometrist's written instruction, as for the grinding of corrective lenses.
3. A formula directing the preparation of something.
4. Law. The process of acquiring title to property by reason of uninterrupted possession of specified duration. Also called positive prescription.
5. Law. The limitation of time beyond which an action, debt, or crime is no longer valid or enforceable. Also called negative prescription.

[Middle English prescripcion, establishment of a claim, from Old French prescription, from Medieval Latin praescrīptiō, praescrīptiōn-, from Latin, introduction, precept, from praescrīptus, past participle of praescrībere, to order. See prescribe.]

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.