a substance used in dough to make it rise, such as yeast or baking powder

during the 18th century yeast was abandoned as a leavening for fruit cakes

everything will be made with natural leavening and wholegrain flour

a quality or element that permeates and modifies or transforms something for the better

underneath the frills and fuss there's a leavening of serious intent

cause (dough or bread) to rise by adding yeast or another raising agent

it only take a little bit of yeast to leaven the bread

permeate and modify or transform (something) for the better

the proceedings should be leavened by humour