armadillo UK /ɑːməˈdɪləʊ/US /ɑɹməˈdɪloʊ/ noun1 •Any of the burrowing mammals in the families Dasypodidae, Chlamyphoridae, Tolypeutidae and Euphractidae in the order Cingulata, found in the Americas, especially South America, and covered with bony, jointed protective plates. formsarmadilloes · armadillos