cactus

American  

[kak-tuhs] / ˈkæk təs /

noun

plural

cacti, cactuses, cactus

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

• cactaceous adjective
• cactoid adjective
• cactuslike adjective

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

Attendees wearing cowboy hats line danced, petted fluffy white calves and posed for pictures in front of an inflated cactus.

From Los Angeles Times • Apr. 12, 2026

The video for Opalite premiered on Friday, and stars Irish actor Domhnall Gleeson as a "lonely man" who summons Swift into his life by spraying a magic potion on his beloved cactus.

From BBC • Feb. 6, 2026

Bezos and Sanchez have placed the sauna, which is understood to have been designed by Timothy Oulton Studio, near the cactus garden.

From MarketWatch • Dec. 26, 2025

They use playa names, such as cactus or fuzzypants, making possible suspects hard to identify.

From Salon • Oct. 27, 2025

I introduced Zion to Josephine and Henry, shot a rubber snake at the shooting range, and even stuck my face through a wooden painting of a cactus so Zion could take a picture.

From "Insignificant Events in the Life of a Cactus" by Dusti Bowling