“ Eng. levain, adapted from Fr. levain, in same sense, from Lat. levamen, which is only found in the sense of alleviation, comfort, levare, to lift up) , a substance which produces fermentation, particularly in the making of bread, properly a portion of already fermented dough added to other dough for this purpose (see Bread) . The word is used figuratively of any element, influence or agency which effects a subtle or secret change. ”