noun (plural cirri /ˈsirˌī/ /ˈsirē/)
1Cloud forming wispy filamentous tufted streaks (“mare’s tails”) at high altitude, usually 16,500–45,000 feet (5-13 km).
- 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 hairlike filament, such as the appendage of a barnacle, the barbel of a fish, or the intromittent organ of an earthworm.
- 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 cirrusPyrrhus
For editors and proofreaders
Definition of cirrus in:
What do you find interesting about this word or phrase?
Comments that don't adhere to our Community Guidelines may be moderated or removed.