1. To pinch or press two pastry edges together, thereby sealing the dough while forming a decorative edge with fingers, fork or other utensil. The pastry for a single-crust pie is crimped by turning it under to form a ridge, then shaping (or fluting) the raised edge into a fancy pattern. A raised crimped edge not only seals the pastry but acts like a dam to contain the filling during cooking. 2. To cut gashes at 1- or 2-inch intervals along both sides of a freshly caught fish. The fish is then soaked in ice water for up to an hour. Crimping a fish creates a firmer-textured flesh and skin that quickly becomes crisp when cooked.
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.