To tie fat, such as bacon or fatback, around lean meats or fowl to prevent their drying out during roasting. Barding is necessary only when natural fat is absent. The barding fat bastes the meat while it cooks, thereby keeping it moist and adding flavor. The fat is removed a few minutes before the meat is done to allow the meat to brown.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.