RhymeZone: koji definitions

Definitions of koji:

noun: A substance that is produced by letting a mold, especially Aspergillus oryzae, grow on rice, barley, soybeans, etc., used to make fermented products such as sake, amazake, miso, and soy sauce.
noun: The mold used in such a preparation.
noun: A male given name from Japanese

(Definitions from Wiktionary)