• (n.) The portion of the upper crust of a loaf which has touched another loaf in baking.
Kiss'ing·crust` noun (Cookery) The portion of the upper crust of a loaf which has touched another loaf in baking. Lamb. « A massy fragment from the rich kissingcrust that hangs like a fretted cornice from the upper half of the loaf.» W. Howitt.