cirrus

American  

[sir-uhs] / ˈsɪr əs /

noun

plural

cirrus, cirri

1. Meteorology.

   1. a cloud of a class characterized by thin white filaments or narrow bands and a composition of ice crystals: of high altitude, about 20,000–40,000 feet (6000–12,000 meters).

   2. a cirriform cloud.

2. Botany. a tendril.

3. Zoology.

   1. a filament or slender appendage serving as a foot, tentacle, barbel, etc.

   2. the male copulatory organ of flatworms and various other invertebrates.

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cirrus British  

/ ˈsɪrəs /

noun

1. meteorol a thin wispy fibrous cloud at high altitudes, composed of ice particles

2. a plant tendril or similar part

3. zoology

   1. a slender tentacle or filament in barnacles and other marine invertebrates

   2. a hairlike structure in other animals, such as a filament on the appendage of an insect or a barbel of a fish

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cirrus Scientific  

/ sîr′əs /

plural

cirri

1. A high-altitude cloud composed of feathery white patches or bands of ice crystals. Cirrus clouds generally form between 6,100 and 12,200 m (20,000 and 40,000 ft).

2. See illustration at cloud

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Etymology

Origin of cirrus

1700–10; < Latin: a curl, tuft, plant filament like a tuft of hair

Example Sentences

These recent events, however, have only amplified trends that had begun building earlier in the year, Cirrus Research Chief Executive Satya Pradhuman says.

From Barron's • Mar. 5, 2026

The Cirrus SR 20 is known to deploy a parachute system and images circulating online after the crash appeared to show a yellow parachute canopy caught in a pylon nearby.

From BBC • Feb. 3, 2026

As medical centers move to the Cirrus system, doctors need a dependable way to translate measurements so they can compare results over time.

From Science Daily • Nov. 14, 2025

Realizing it was too late to restart the engine, the pilot deployed the airplane’s Cirrus Airframe Parachute System, which slowed the airplane’s descent, the press release said.

From Los Angeles Times • Mar. 13, 2024

One of these balloons, the "Cirrus," among several trials, rose to a height, self-registered, of 61,000 feet, while a possible greater height has been accorded to it.

From The Dominion of the Air; the story of aerial navigation by Bacon, John Mackenzie