narco Syllabification: (nar·co)Pronunciation: /ˈnärkō/Definition of narco noun (plural narcos) US informal narcotics; illegal drugs: [as modifier]:the multi-billion dollar narco trade a dealer in drugs:political bosses who may have links to the narcosOrigin: 1950s: abbreviation of narcoticnarco in other Oxford dictionaries Definition of narco in the British & World English dictionary