n. An American edentate quadruped, of the order Bruta (or Edentata) and suborder Loricata, and of the extant families Tatusiidœ, Dasypodidœ, and Chlamydophoridœ, or of the extinct family Glyptodontidœ, having a hard shell or carapace like a coat of mail, resulting from a peculiar ossification of the integument and the confluence of numerous small scutes.n. In Crustacea: A genus of isopods, of the family Oniscidœ, including the pillbugs, which can roll themselves into a ball like the mammals called armadillos.n. A species of this genus; a pill-bug or sow-bug; a kind of wood-louse.n. A name given to an electric battery composed of copper and zinc elements riveted together, and designed to be worn as a remedy in certain diseases.