Judaism (n.) Look up Judaism at Dictionary.com
c.1400 (attested in Anglo-Latin from mid-13c.), from Old French Judaisme and directly from Late Latin Judaismus (Tertullian), from Greek Ioudaismos, from Ioudaios "Jew" (see Jew). The Anglo-Latin reference is from a special tax levied on the Jews of England. Earlier in same sense was Juhede "Jewish faith, Judaism," literally "Jew-hood" (early 14c.).