Pronunciation: (lev'u-ning), [key]
1. Also called leav'ening a"gent. a substance used to produce fermentation in dough or batter; leaven.
2. the act or process of causing to ferment by leaven.
3. leaven (def. 3).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.