1. 1. The formation of a close human relationship, as between friends: "He says he has rediscovered the comforts of male bonding in a Washington men's group" (Marilyn Chase).
   2. The emotional and physical attachment occurring between a parent or parent figure, especially a mother, and offspring, that usually begins at birth and is the basis for further emotional affiliation.
2. 1. A dental technique in which a material such as plastic or porcelain is attached to the surface of a discolored or damaged tooth.
   2. The technique of using adhesives to attach orthodontic brackets or other appliances to the teeth.

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.