v. cause to rise, especially by fermentation; add a rising agent to
When we leaven bread dough, it puffs up, expanding in volume.
The Dark World is a looser, loopier hybrid of science fiction and fantasy powered by a pair of magnetic performances and leavened with a number of truly witty moments.
Sentence in Classic:
In the professions, college men are slowly but surely leavening the Negro church, are healing and preventing the devastations of disease, and beginning to furnish legal protection for the liberty and property of the toiling masses.
The Souls of Black Folk By W. E. B. Du Bois Context