Zabaglione - An Italian dessert made from egg yolks, wine, and sugar. Zabaglione is beaten over simmering water, which cooks the egg yolks and makes a light and foamy custard. Recipe: Zabaglione

Zest - The thin, brightly colored outer skin of a citrus fruit (not the white part). A citrus zester or paring knife may be used to remove the thin layer, usually in small shreds. Zest adds a nice citrus flavor to dishes and baked goods.
Recipe: Lemon Sponge Pie

Zuppa - Italian word for "soup."
Recipe: Zuppa di Spinaci

Zwieback - Zwieback means "twice baked" in German, and refers to cut up bread which is then cooked in the oven until thoroughly crisped and dry.