Definition of cirrus in English:

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Pronunciation: /ˈsɪrəs/

noun (plural cirri /ˈsɪrʌɪ/)

1 [mass noun] Cloud forming wispy filamentous tufted streaks or ‘mare’s tails’ at high altitude (usually 5 to 13 km, 16,500 to 45,000 ft): long strands of high cirrus stretched across the eastern sky [as modifier]: cirrus clouds
More example sentences
  • The basic cloud forms are cumulus, which are heaped clouds; stratus, which are layer clouds; and cirrus, which are wispy.
  • In the troposphere, water exists as vapor in air, as liquid droplets in clouds, and as frozen ice particles in high altitude cirrus clouds.
  • The formation of wispy cirrus clouds is not a simple matter.
2 Zoology A slender tendril or hair-like filament, such as the appendage of a barnacle, the barbel of a fish, or the intromittent organ of an earthworm.
Example sentences
  • Once the barnacles extended their cirri (fanlike, food-gathering appendages) and started waving them about to collect nutritious particles in the water, the researchers cast a shadow over them with a piece of cardboard.
  • Other common elements may include the possession of fixed conical teeth and cirri, or fleshy hair-like projections, on the head.
  • The head is often blunt and typically adorned with tentacles or cirri.
2.1 Botany A tendril.







Early 18th century (in the sense 'tendril'): from Latin, literally 'a curl'.

Words that rhyme with cirrus


For editors and proofreaders

Line breaks: cir¦rus

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