1. The act or process of inserting.
2. Something inserted, as an ornamental strip of lace or embroidery inserted between pieces of fabric.
3. Anatomy. The point or mode of attachment of a skeletal muscle to the bone or other body part that it moves.
4. Genetics. The addition, as by mutation, of one or more nucleotides to a chromosome.

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.