1. A ferment to make dough rise and impart a spongy texture to the bread; anything which pervades a mass and changes its nature, generally for the worse.

2. To raise with leaven; to imbue; to taint.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• lesen,
• leavl,
• leagon,
• leaeve,
• learnen,
• lawen,
• eaven,
• leaveor,
• ledgen,
• leavor,
• leavve,
• lieave,
• layen,
• leavung,
• leapin,
• leavel,
• leeave,
• heavean,
• luaren,
• leavong

• leaving,
• levee,
• Levine,
• Leaves,
• Leven,
• learn,
• Levin,
• lever,
• laven,
• Lavenia,
• even,
• leave,
• lean,
• heaven,
• eleven,
• levene,
• levan.

The adverb form of "leaven" is "leavenedly".

The adjective form of the word "leaven" is "leavened".

The plural form of the word "leaven" is "leavens"

The singular form of the word "leaven" is "leaven". The word does not change in its singular form.