say it: LEV-uhn
leaven is a noun and verb meaning "a substance used to produce fermentation in dough or a liquid". It carries 3 recorded senses.
a substance used to produce fermentation in dough or a liquid
an influence that works subtly to lighten or modify something
“his sermons benefited from a leavening of humor”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for leaven come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.