noun Botany, Zoology.

a plural of cirrus.


[sir-uh s]

noun, plural cir·rus for 1, cir·ri [sir-ahy] /ˈsɪr aɪ/ for 2, 3.

  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.
Botany. a tendril.
  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


variant of cirro-. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for cirri

clasp, coil, curl, ringlet, cirrus

Examples from the Web for cirri

Historical Examples of cirri

British Dictionary definitions for cirri



the plural of cirrus


noun plural -ri (-raɪ)

meteorol a thin wispy fibrous cloud at high altitudes, composed of ice particles
a plant tendril or similar part
  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 cirri



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

cirri in Science



Plural cirri (sîrī′)

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.