I. ˈle-vən noun
Etymology: Middle English levain, from Anglo-French levein, from Vulgar Latin * levamen, from Latin levare to raise — more at lever
Date: 14th century
1.
a. : a substance (as yeast) used to produce fermentation in dough or a liquid ; especially : sourdough
b. : a material (as baking powder) used to produce a gas that lightens dough or batter
2. : something that modifies or lightens
II. transitive verb
( leav·ened ; leav·en·ing ˈlev-niŋ, ˈle-və-)
Date: 15th century
1. : to raise (as bread) with a leaven
2. : to mingle or permeate with some modifying, alleviating, or vivifying element ; especially : lighten
a sermon leaven ed with humor
Synonyms: see infuse