cac·tus [cactuscacticactuses] BrE [ˈkæktəs] NAmE [ˈkæktəs] noun (pl. cac·tusesor cactiBrE [ˈkæktaɪ] ; NAmE [ˈkæktaɪ] ) a plant that grows in hot dry regions, especially one with thick ↑stems covered in ↑spines but without leaves. There are many different types of cactus.
Word Origin: early 17th cent.: from Latin, from Greek kaktos ‘cardoon’ (a tall plant with leaves and roots that can be eaten as a vegetable).