1. The act, practice, or profession of instructing.
2. 1. Imparted knowledge.
   2. An imparted or acquired item of knowledge; a lesson.
3. Computer Science. A sequence of bits that tells a central processing unit to perform a particular operation and can contain data to be used in the operation.
4. 1. An authoritative direction to be obeyed; an order. Often used in the plural: had instructions to be home by midnight.
   2. instructions Detailed directions on procedure: read the instructions for assembly.

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.