any succulent plant of the family Cactaceae native chiefly to arid regions of the New World and usually having spines
"The prickly cactus thrived in the hot, dry desert soil."
Any member of the family Cactaceae, a family of flowering New World succulent plants suited to a hot, semi-desert climate.
"The prickly pear cactus thrived in the hot, semi-desert landscape under the bright sun."
In plain English: A cactus is a tough plant with spiky skin that grows dry places and stores water inside its thick body to survive without much rain.
"The desert cactus stood tall and green in the hot sun."
Usage: Do not confuse this plant with "cactus," which is often mistakenly used as an adjective; the correct botanical term for the non-functional or broken state of machinery is simply "dead" or "broken." Additionally, avoid using it to describe a person who has given up on life, as that usage is informal and potentially offensive.
Non-functional, broken, exhausted, dead.
"After years of neglect, his passion had turned him into a cactus, unable to grow or respond to anything around him."
In plain English: There is no adjective form of cactus because it is only used as a noun to name the plant.
"There is no such thing as an adjective form for cactus in standard English; this word functions only as a noun to describe the plant itself."
A city in Texas.
"The residents of Cactus, Texas, gathered at the town square to celebrate their annual harvest festival."
The word "cactus" entered English in 1752 when Carl Linnaeus adopted a Latinized form of the ancient Greek word kaktos, which originally referred to a cardoon plant. Although the genus name has since been superseded by Mammillaria, the term remains familiar for the spiky plants we know today.