leaven

Meanings

1. 1
   noun

   an influence that works subtly to lighten or modify something

   The sermons benefited from the leaven of humor.

2. 2
   verb

   cause to puff up with a leaven

   unleavened bread

3. 3
   noun

   Anything that induces change, especially a corrupting or vitiating change.

   Take heed, beware of the leaven of the Pharisees, and of the leaven of Herod.

4. 4
   noun

   Chametz.

   On the fourteenth day of Nisan men search for leaven by candlelight.

5. 5
   verb

   To add a leavening agent.

   Yeast is used to leaven bread, making it rise during baking.

6. 6
   verb

   To temper an action, decision, attitude, characteristic, etc.

   Duke. No more euasion: We haue with a leauen'd, and prepared choice Proceeded to you; therefore take your honors:[...]

7. 7
   verb

   To imbue; to infect; to vitiate.

   The comedian's jokes helped leaven the atmosphere during the serious meeting.

8. 8
   noun

   a substance used to produce fermentation in dough or a liquid

Etymology

From Middle English levayn, borrowed from Old French levain, from Vulgar Latin *levāmen, a noun based on Latin levō (“raise”).