The Collaborative International Dictionary of English v.0.48:
Leaven \Leav"en\, v. t. [imp. & p. p. Leavened; p. pr. & vb. n. Leavening.] 1. To make light by the action of leaven; to cause to ferment. [1913 Webster] A little leaven leaveneth the whole lump. --1 Cor. v. 6. [1913 Webster] 2. To imbue; to infect; to vitiate. [1913 Webster] With these and the like deceivable doctrines, he leavens also his prayer. --Milton. [1913 Webster]The Collaborative International Dictionary of English v.0.48:
leavened \leavened\ adj. made light by aerating, as with yeast or baking powder. Opposite of unleavened. [Narrower terms: sourdough(prenominal) ] [WordNet 1.5]WordNet (r) 3.0 (2006):
leavened adj 1: made light by aerating, as with yeast or baking powder; often used as a combining form; "leavened bread"; "well- leavened"; "yeast-leavened breads" [ant: {unleavened, unraised]