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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:

On the 13th floor of a high rise, elevators open up to a light-filled office with cactus plants, a small library and a coffee bar.

From The Wall Street Journal ● Sep. 20, 2026

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

From Los Angeles Times ● Sep. 2, 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

But in 2010 he was approached by traders looking for a very different crop - the cactus agave americana.

From BBC ● Jun. 11, 2026

A short distance from the bottom, the path curved around a large potted cactus.

From "The Mysterious Benedict Society" by Trenton Lee Stewart

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

For others, like cacti and succulents, Clare says we mistakenly drown them by unnecessarily watering them.

From BBC ● Jan. 14, 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 hillside around Robert Dickran’s home in Camarillo Heights was dotted with burnt cacti and charred brush, showing just how close the fire came to his home.

From Los Angeles Times ● Nov. 10, 2024

Although cacti may sound more scientific, it’s not more correct; in fact, cactuses is more common among nonscientists.

From "Woe Is I" by Patricia T. O'Conner

The facade has vertical ridges running down the side, which Diamond said was inspired by the ribs of Saguaro cactuses.

From The Wall Street Journal ● Jul. 12, 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

Rather than a watery grave, however, a mysterious moonlit desert is where she’s adrift, a row of spiky cactuses behind her appearing to pierce her body.

From Los Angeles Times ● Dec. 9, 2024

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

We had all seen the clumps of prickly pear cactuses that were growing everywhere.

From "Code Talker: A Novel About the Navajo Marines of World War Two" by Joseph Bruchac

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