a substance used to produce fermentation in dough or a liquid
source: WordNet 3.0
an influence that works subtly to lighten or modify something
His sermons benefited from a leavening of humor.
source: WordNet 3.0
Any substance that produces, or is designed to produce, fermentation, as in dough or liquids; esp., a portion of fermenting dough, which, mixed with a larger quantity of dough, produces a general change in the mass, and renders it light; yeast; barm.
source: Webster 1913
verb
cause to puff up with a leaven
Unleavened bread.
source: WordNet 3.0
To make light by the action of leaven; to cause to ferment.
