1. 1. The act or process of differentiating.
   2. The state of becoming differentiated.
2. Mathematics. The process of computing a derivative.
3. Biology. The process by which cells or tissues undergo a change toward a more specialized form or function, especially during embryonic development.

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.