leaven
1. [ noun ] a substance used to produce fermentation in dough or a liquid
Synonyms: leavening
Related terms: substance sourdough baking_powder yeast raise
2. [ verb ] cause to puff up with a leaven; of dough
Synonyms: prove raise
Examples:

"unleavened bread"

Related terms: raise rise
3. [ noun ] an influence that works subtly to lighten or modify something
Synonyms: leavening
Examples:

"his sermons benefited from a leavening of humor"

Related terms: imponderable
Similar spelling:   Leven
  Levene
  Levin
  Levan
  Levine
  Laven
  Lavenia