- a substance, as yeast or baking powder, that causes fermentation and expansion of dough or batter.
- fermented dough reserved for producing fermentation in a new batch of dough.
- an element that produces an altering or transforming influence.
- to add leaven to (dough or batter) and cause to rise.
- to permeate with an altering or transforming element.
- any substance that produces fermentation in dough or batter, such as yeast, and causes it to rise
- a piece of such a substance kept to ferment a new batch of dough
- an agency or influence that produces a gradual change
- to cause fermentation in (dough or batter)
- to pervade, causing a gradual change, esp with some moderating or enlivening influence
