Definition of cirrus
1 : tendril
2 : a slender usually flexible animal appendage or projection: such asa : an arm of a barnacleb : a filament of a crinoidc : a fused group of cilia functioning like a limb on some protozoansd : the male copulatory organ of various invertebrate animals
3 : a high wispy white cloud usually of minute ice crystals formed at altitudes between about 20,000 and 40,000 feet (6,000 and 12,000 meters) — see cloud illustration
Recent Examples of cirrus from the Web
Nearly horizontal ice particles in cirrus clouds that are 3- to 5-miles high up in the atmosphere.
One telltale clue, per Tech Times: The scientists found that the flashes seemed to occur around high-floating cirrus clouds, and those clouds are made up of ice crystals.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cirrus'. Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
Origin and Etymology of cirrus
New Latin, from Latin, curl
First Known Use: 1708See Words from the same year
CIRRUS Defined for English Language Learners
Definition of cirrus for English Language Learners
: a thin type of cloud that forms high in the sky
CIRRUS Defined for Kids
Definition of cirrus for Students
: a thin white cloud of tiny ice crystals that forms at a very high altitude
Seen and Heard
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