Meaning

noun usually coiled

noun a wispy white cloud (usually of fine ice crystals) at a high altitude (4 to 8 miles)

noun a slender flexible animal appendage as on barnacles or crinoids or many insects; often tactile

originLearned borrowing from Latin cirrus (“curl; fringe of clothes; mane (especially forelock) of a horse; etc”); further etymology unknown. Sense 2 (“type of cloud”) was coined by the British chemist and amateur meteorologist Luke Howard (1772–1864): see the 1803 quotation. The plural form cirri is also a learned borrowing from Latin cirrī, the nominative or vocative plural of cirrus.

Etymology from Wiktionary, CC BY-SA 3.0