Also found in: Dictionary, Thesaurus, Medical, Acronyms, Wikipedia.
Related to cirrus: cirrus cloud
1. Meteorol a thin wispy fibrous cloud at high altitudes, composed of ice particles
2. a plant tendril or similar part
a. a slender tentacle or filament in barnacles and other marine invertebrates
b. a hairlike structure in other animals, such as a filament on the appendage of an insect or a barbel of a fish
The conical locomotor structure composed of fused cilia in hypotrich protozoans.
Any of the jointed thoracic appendages of barnacles.
Any hairlike tuft on insect appendages.
The male copulatory organ in some mollusks and trematodes.
Any of the tactile barbels of certain fishes.
A tendrillike animal appendage.
Thin, separated or detached clouds appearing in all seasons. They are often feathery, fibrous, or tufted in appearance. They are high clouds, which occur at above 20,000 ft (6 km) height. Cirrus clouds are composed of thin crystals or needles of ice, not droplets of water. These clouds are represented on the weather map by symbols like and . The former means that the amount of cirrus is not increasing, whereas the latter means that it is a dense cirrus cloud but it does not form an anvil of a cumulonimbus cloud.