Definition of cactus

• n. - Any plant of the order Cactacae, as the prickly pear and the night-blooming cereus. See Cereus. They usually have leafless stems and branches, often beset with clustered thorns, and are mostly natives of the warmer parts of America.
• n. - Any plant of the order Cactacae, as the prickly pear and the night-blooming cereus. See Cereus. They usually have leafless stems and branches, often beset with clustered thorns, and are mostly natives of the warmer parts of America.