Wiktionary(0.00 / 0 votes)Rate this definition: 1  euro(Noun) The currency unit of the European Monetary Union. Symbol: u20AC. 2  euro(Noun) A coin with a facial value of 1 euro. 3  euro. A caucasoid.  euro(Noun) Macrobius robustus, a wallaroo (macropod 1  species). Euro(Noun) , the currency and coin introduced 1996.