taco Syllabification: (ta·co)Pronunciation: /ˈtäkō/Definition of taco noun (plural tacos) a Mexican dish consisting of a fried tortilla, typically folded, filled with various mixtures, such as seasoned meat, beans, lettuce, and tomatoes. Origin:Mexican Spanish, from Spanish, literally 'plug, wad'Make the plural of taco in the usual way, by adding -s: (tacos).taco in other Oxford dictionaries Definition of taco in the British & World English dictionary