[sir-uh s]
See more synonyms for cirrus on
noun, plural cir·rus for 1, cir·ri [sir-ahy] /ˈsɪr aɪ/ for 2, 3.
  1. Meteorology.
    1. a cloud of a class characterized by thin white filaments or narrow bands and a composition of ice crystals: of high altitude, about 20,000–40,000 feet (6000–12,000 meters).
    2. a cirriform cloud.
  2. Botany. a tendril.
  3. Zoology.
    1. a filament or slender appendage serving as a foot, tentacle, barbel, etc.
    2. the male copulatory organ of flatworms and various other invertebrates.

Origin of cirrus

1700–10; < Latin: a curl, tuft, plant filament like a tuft of hair Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for cirrus

clasp, coil, curl, ringlet, cirrus

Examples from the Web for cirrus

Historical Examples of cirrus

British Dictionary definitions for cirrus


noun plural -ri (-raɪ)
  1. meteorol a thin wispy fibrous cloud at high altitudes, composed of ice particles
  2. a plant tendril or similar part
  3. zoology
    1. a slender tentacle or filament in barnacles and other marine invertebrates
    2. a hairlike structure in other animals, such as a filament on the appendage of an insect or a barbel of a fish

Word Origin for cirrus

C18: from Latin: curl, tuft, fringe
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for cirrus

1708, "curl-like fringe or tuft," from Latin cirrus "a lock of hair, tendril, curl, ringlet of hair; the fringe of a garment." In meteorology, cirrus clouds attested from 1803. So called from fancied resemblance of shape.

Online Etymology Dictionary, © 2010 Douglas Harper

cirrus in Science


Plural cirri (sîrī′)
  1. A high-altitude cloud composed of feathery white patches or bands of ice crystals. Cirrus clouds generally form between 6,100 and 12,200 m (20,000 and 40,000 ft). See illustration at cloud.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.