cirrus

[ sir-uhs ]

noun

, plural cir·rus cir·ri [sir, -ahy]

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.

cirrus

/ 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

cirrus

/ sîr′əs /

, Plural cirri sîr′ī′

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

Word History and Origins

Origin of cirrus¹

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

Word History and Origins

Origin of cirrus¹

C18: from Latin: curl, tuft, fringe

Example Sentences

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

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

Those harmless-looking vapor trails sometimes spread out to form thin cirrus clouds.

From Seattle Times

Soot triggers the formation of contrails and 'contrail cirrus', which are line-shaped clouds produced by aircraft engine exhaust.

From Science Daily

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

From Scientific American