The Collaborative International Dictionary
Zythum
Zythum \Zy"thum\ (z[i^]"th[u^]m), n. [L., fr. Gr. zy^qos a kind of beer; -- so called by the Egyptians.] A kind of ancient malt beverage; a liquor made from malt and wheat. [Written also zythem.]
Wiktionary
zythum
n. Egyptian malt beer, which is noted for being ferment.