1. leaven - Noun
2. leaven - Verb
Any substance that produces, or is designed to produce, fermentation, as in dough or liquids; esp., a portion of fermenting dough, which, mixed with a larger quantity of dough, produces a general change in the mass, and renders it light; yeast; barm.
Anything which makes a general assimilating (especially a corrupting) change in the mass.
To make light by the action of leaven; to cause to ferment.
To imbue; to infect; to vitiate.
Source: Webster's dictionaryhis sermons benefited from a leavening of humor Source: Internet
unleavened bread Source: Internet
Although these are defined in English as leavening agents, they leaven by chemical reaction, not by biological fermentation. Source: Internet
Before Passover, Jewish families eliminate all foods containing leaven () from their homes, in imitation of the Israelites who had to flee in haste (). Source: Internet
At this new dawn marked by her 60th year, Lourdes School of Mandaluyong renews its commitment to form authentic Christian gentlemen who are light, salt, and leaven to the world. Source: Internet
A blessed minority, that is once more invited to leaven, to rise in harmony with what the Holy Spirit inspired in the heart of your founders, and in your hearts. Source: Internet