/ Dictionary / Index C cactus: Meaning and Definition of Find definitions for: cac•tus Pronunciation: (kak'tus), [key] — pl. -ti -tus•es, -tus. any of numerous succulent plants of the family Cactaceae, of warm, arid regions of the New World, having fleshy, leafless, usually spiny stems, and typically having solitary, showy flowers. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: cactus (Thesaurus) cactaceous cactus dahlia Related Content Daily Word Quiz: diaphanous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language