cirrus

1 of 2

noun

cir·​rus ˈsir-əs 

plural cirri ˈsir-ˌī 

1

: tendril

2

: a slender usually flexible animal appendage or projection: such 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

cirr-

2 of 2

combining form

variants or cirri- or cirro- or less commonly cirrhi- or cirrho-

1

: cirrus of a plant or animal

cirriferous

cirrigrade

2

: cirrus cloud

cirrostratus

Examples of cirrus in a Sentence

Recent Examples on the Web

Noun

There wasn’t a single cloud in the sky, not even a cirrus wisp or fading contrail. — Ross Andersen, The Atlantic, 11 July 2024

As the pulse locks in, organ drones arc overhead like streaking cirrus clouds. — Dash Lewis, Pitchfork, 29 Jan. 2026

Inside, cirrus clouds are comprised almost entirely of ice crystals. — Noel Kirkpatrick, Treehugger, 7 Aug. 2025

This energetic cirrus scent smells like the heart of summer, ripe juicy lemons, and tangerine offset by apple and jasmine. — Rose Dommu, Them, 11 Dec. 2024

Word History

Etymology

Noun

New Latin, from Latin, curl

Combining form

Latin cirrus curl

First Known Use

Noun

1708, in the meaning defined at sense 1

Rhymes for cirrus

• cuirass
• pyrus
• papyrus
• veneris

Kids Definition

cirrus

noun

cir·​rus ˈsir-əs 

plural cirri ˈsi(ə)r-ˌī 

: a thin white cloud usually of tiny ice crystals formed at altitudes about 20,000 to 40,000 feet (6,000 to 12,000 meters)

Medical Definition

cirrus

noun

cir·​rus ˈsir-əs 

plural cirri ˈsi(ə)r-ˌī 

: a slender usually flexible animal appendage: as

a

: a fused group of cilia functioning like a limb on some protozoans

b

: the male copulatory organ of some worms