transitive verb

  1. to produce fermentation in (dough or batter), consequently causing the dough or batter to rise in the process of baking.
    The dough is leavened with yeast.
  2. to enliven or change with a subtle, pervasive influence.
    The story is leavened by her sense of comic irony.

noun

  1. a substance, such as yeast, that produces fermentation in a dough or batter and causes it to rise.
  2. an element that has a subtle, enlivening, or modifying effect; leavening.
    the leaven of humor.

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