n. (pl. cacti or cactuses) any succulent plant of the family Cactaceae, with a thick fleshy stem, usu. spines but no leaves, and brilliantly coloured flowers.
Phrases and idioms:
cactus dahlia any kind of dahlia with quilled petals resembling a cactus flower.
Derivatives:
cactaceous adj.
Etymology: L f. Gk kaktos cardoon