saguaro Syllabification: (sa·gua·ro)Pronunciation: /səˈ(g)wärō/ (also saguaro cactus)Definition of saguaro noun (plural saguaros) a giant cactus that can grow to 66 feet (20 m) in height and whose branches are shaped like candelabra, native to Mexico and the southwestern US. Its reddish-purple fruit can be used for food and drink. Carnegiea gigantea, family Cactaceae Origin: mid 19th century: from Mexican Spanishsaguaro in other Oxford dictionaries Definition of saguaro in the British & World English dictionary