fiscPronunciation: /fɪsk/Definition of fisc noun Roman History the public treasury of Rome or the emperor’s privy purse. archaic & North American a public treasury or exchequer. (also fisk) Scottish archaic the public treasury to which estates lapse by escheat. Origin: late 16th century: from French, or from Latin fiscus 'rush basket, purse, treasury'fisc in other Oxford dictionaries Definition of fisc in the US English dictionary