Main Entry: cir·rus

Pronunciation: \ˈsir-əs\

Function: noun

Inflected Form(s): plural cir·ri \ˈsir-ˌī\

Etymology: New Latin, from Latin, curl

Date: 1708

1 : tendril
2 : a slender usually flexible animal appendage or projection: as a : an arm of a barnacle b : a filament of a crinoid c : a fused group of cilia functioning like a limb on some protozoans d : 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