leaven /'levn; 'levan/ n [U] substance, eg yeast, used to make dough rise before it is baked to make bread; (fig) quality or influence spreading in and changing sth. 酵母; 酵素; (喻)散布其間而具看改變力量的性質(zhì)或影審力。口巧 [VP6A] add ~ to; act like ~ upon. 加以酵母; 使發(fā)酵; 影響。