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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.


cactus British  
/ 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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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

Inflected Forms

Nouns

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.

Keep Reading on Vocabulary.com

Vocabulary lists containing cactus

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

They say diamonds are forever, but in her hands, plumeria blooms and cactus blossoms can be too.

From Los Angeles Times ● Sep. 2, 2026

At its center is a compact red source that closely resembles a little red dot and even evokes the ruby red fruit of the desert cactus.

From Science Daily ● Aug. 17, 2026

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

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

In fact, there was a string of cactus petals flowing behind them, erasing them from the ground.

From "Healer of the Water Monster" by Brian Young

To visually take us there, it uses the headline "prickly heat", calling to mind the cacti of Arizona.

From BBC ● Jun. 26, 2026

However, researchers at the University of Reading found that cacti follow a different pattern.

From Science Daily ● May 13, 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

Orchard Hills’ zone is filled with prickly pear cacti, Japanese honeysuckle and Formosa firethorn.

From Los Angeles Times ● Feb. 19, 2025

I was walking along a street one afternoon when I saw a piece of magazine impaled against a fence of cacti.

From "Kaffir Boy: An Autobiography" by Mark Mathabane

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

In describing the cactuses and the palm trees, he notes “the laciness of it all. … It has a magic to it that attracted me.”

From Los Angeles Times ● Aug. 7, 2024

You walk around the house with your hood pulled tight and stop in front of your dad’s cactuses.

From "Goodbye Stranger" by Rebecca Stead

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