To create an emulsion by reducing all the particles to the same size. In homogenized milk, for instance, the fat globules are broken down mechanically until they are evenly and imperceptibly distributed throughout the liquid. Commercial salad dressings are also often homogenized.
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.