cactus

American  

[kak-tuhs] / ˈkæk təs /

noun

cacti, plural cactuses, plural cactus plural

1. 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.

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cactus British  

/ kækˈteɪʃəs, ˈkæktəs /

noun

1. any spiny succulent plant of the family Cactaceae of the arid regions of America. Cactuses have swollen tough stems, leaves reduced to spines or scales, and often large brightly coloured flowers

2. a double-flowered variety of dahlia

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Usage

Plural word for cactus The plural form of cactus can be either cacti, cactuses, or cactus. Cacti is most commonly used. Like many words derived from Latin, it is pluralized by replacing the -us ending with -i, as in fungus/fungi and nucleus/nuclei. However, the plural form cactuses, created by adding the typical -es to the end, is also correct. This alternative plural form is also acceptable for some other Latin-derived or related terms, as in focus/foci/focuses and radius/radii/radiuses.

Other Word Forms

Derived Forms

• cactaceous
  adjective
• cactoid
  adjective
• cactuslike
  adjective

Inflected Forms

Nouns

• cacti
  plural
• cactus
  plural
• cactuses
  plural

Etymology

Origin of cactus

1600–10; < Latin < Greek káktos cardoon

Explanation

A cactus is a succulent desert plant that's often covered in sharp spines. Some cacti grow brilliantly colored flowers, but none of them have leaves. You can grow an indoor cactus in a pot — it's a fairly easy plant to care for, since it prefers to be watered infrequently. Cacti are able to conserve water, which is why they do well in very dry environments, like the American Southwest. The Greek root of cactus is kaktos, the name of a specific spiky Sicilian plant.

Example Sentences

See Examples For:

cactus cacti cactuses

The nopal cactus is cast from a real nopal and hand-poured in 100% pure beeswax in the Los Angeles studio.

From Los Angeles Times ● Jul. 1, 2026

She has a piece with prickly pear cactus as well as datura in it, which is crazy.

From Los Angeles Times ● Jun. 17, 2026

For him and his fellow farmers the agave cactus was just a "stubborn, valueless weed" - planted as fencing to keep wild animals off their crops.

From BBC ● Jun. 11, 2026

The research team analyzed flower length data from more than 750 cactus species.

From Science Daily ● May 13, 2026

Wind Being waved goodbye, and its human form disintegrated into strings of wind carrying cactus flower petals and sand.

From "Healer of the Water Monster" by Brian Young

New research shows that cacti are remarkably quick at forming entirely new species, revealing that deserts are far more dynamic than they may seem.

From Science Daily ● May 13, 2026

Pink poodles with long black eyelashes danced in a can-can line, a quartet of googly-eyed cacti bobbed along to the music and a trio of small white dogs galloped on the stage.

From Los Angeles Times ● Apr. 16, 2026

The streets of the Catalina Foothills are lined with Arizona's iconic, giant three-armed Saguaro cacti – and throngs of journalists, investigators and neighbours fixated on the disappearance of the mother of TV presenter Savannah Guthrie.

From BBC ● Feb. 7, 2026

Inside, the gardens are divided into houses highlighting different plants and climates — from the Palm House with over 70 palms, to the fern room, to the desert house filled with cacti and succulents.

From Salon ● Sep. 29, 2025

The only color was some dark, spindly bushes and spiney cacti.

From "Lupita Mañana" by Patricia Beatty

PHOENIX—On a desolate stretch of land dotted with cactuses some 30 minutes north of Phoenix, more than 30 cranes tower over a construction site 2½ times the size of New York City’s Central Park.

From The Wall Street Journal ● Feb. 24, 2026

Among the cactuses in the desert of Arizona, just outside Phoenix, an extraordinary collection of buildings is emerging that will shape the future of the global economy and the world.

From BBC ● May 18, 2025

After a few hours of falling down into desert washes and getting spiked by cactuses, the group realized they were in trouble.

From Salon ● Oct. 4, 2024

Byron Jones, horticulturalist at Tacoma’s Point Defiance Zoo and Aquarium, grows a host of “unthirsty” botanical marvels in the Deserts and Baja Gardens, from sedum and cactuses to agaves and yuccas.

From Seattle Times ● Apr. 12, 2024

And here and there along the paths, flowering cactuses had been planted in great stone pots.

From "The Mysterious Benedict Society" by Trenton Lee Stewart