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

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

Created by Jamie Thompson and ten coauthors from three continents, including six researchers from the University of Reading, the database combines seven years of research on cactus traits, habitats, and evolutionary relationships.

From Science Daily ● May 13, 2026

The film cuts to a hummingbird sipping nectar from a flower on a cactus, a sea turtle floating over a coral reef, pink flamingos on a green lake, a snowflake, a butterfly.

From The Wall Street Journal ● Apr. 16, 2026

She was the faintest scent of a cactus flower, the flitting shadow of an elf owl.

From "Stargirl" by Jerry Spinelli

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

From Science Daily ● May 13, 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

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

There were no cacti anywhere—another oversight on Fatty Bolger’s part, because I looked it up, and cacti are actually native to the Americas.

From "Darius the Great Is Not Okay" by Adib Khorram

Reaching the store requires a 50-mile trek from Phoenix through barren land dotted by cactuses and the occasional sign warning of blowing dust.

From The Wall Street Journal ● May 18, 2026

Among the cactuses in the desert of Arizona, just outside Phoenix, an extraordinary collection of buildings are 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

Rolling hills stretched to the horizon, dotted with oak trees and cactuses and boulders.

From "The Battle of the Labyrinth" by Rick Riordan