cirrus

American  

[sir-uhs] / ˈsɪr əs /

noun

cirrus, plural cirri plural

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 /

cirri plural

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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Other Word Forms

Noun Inflected Forms

• cirri
  plural
• cirrus
  plural

Etymology

Origin of cirrus

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

Example Sentences

See Examples For:

cirrus cirri

The most likely explanation is the presence of thick but uneven water ice clouds, similar to cirrus clouds high in Earth's atmosphere -- an unexpected complication.

From Science Daily ● Apr. 22, 2026

Wind shear can occur in wispy cirrus clouds or even in clear air near thunderstorms, as differences in temperature and pressure create powerful currents of fast-moving air.

From Seattle Times ● May 21, 2024

Sun halos are optical illusions created when ice crystals form in the correct shape in the upper atmosphere, usually accompanying thin, wispy cirrus clouds.

From New York Times ● Apr. 15, 2024

The remaining, thinner cirrus clouds would allow more long-wave radiation emanating from Earth to escape to space.

From Scientific American ● Sep. 20, 2023

He looked at the sky and saw the white cumulus built like friendly piles of ice cream and high above were the thin feathers of the cirrus against the high September sky.

From "The Old Man and The Sea" by Ernest Hemingway

Finally, I may remark that the whole of the body and the cirri are capable of many diversified movements.

From A Monograph on the Sub-class Cirripedia With Figures of all the Species. by Darwin, Charles

C, Highly magnified view of one of the cirri.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" by Various

Margarita, five to seven pairs of epipodial cirri with a pigment spot at base of each.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 5 "Gassendi, Pierre" to "Geocentric" by Various

On the opposite side of the disk the Comatula is covered with plates, arranged regularly around a central plate, which is itself covered with long cirri.

From Seaside Studies in Natural History Marine Animals of Massachusetts Bay. Radiates. by Agassiz, Alexander

Condensation in the whole body of the trade is usually in the form of turbidness or mistiness, a bank or incipient stratus, without cirri.

From The Philosophy of the Weather And a Guide to Its Changes by Butler, Thomas Belden