Leaven - Definition
leaven
n 1: a substance used to produce fermentation in dough or a
liquid [syn: leaven, leavening]
2: an influence that works subtly to lighten or modify
something; "his sermons benefited from a leavening of humor"
[syn: leaven, leavening]
v 1: cause to puff up with a leaven; "unleavened bread" [syn:
raise, leaven, prove]