cirrus

English

WOTD – 23 March 2026

The cirrus (sense 1.1) or tendril of a Jamaican honeysuckle or water lemon (Passiflora laurifolia).

Cirri (sense 1.2) line the stalks of sea lilies (class Crinoidea), here shown anchored to a colony of soft corals (genus Gorgonia) near the island of Roatán, Honduras.

A sky filled with cirrus clouds (sense 2).

Etymology

Learned 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.

Pronunciation

• Singular:
  • (Received Pronunciation, General American) IPA^(key): /ˈsɪɹəs/

  • Audio (Southern England):

    (file)

  • Audio (General American):

    (file)

  • Homophone: cirrous
  • Rhymes: -ɪɹəs
  • Hyphenation: cir‧rus
• Plural:
  • (Received Pronunciation, General American) IPA^(key): /ˈsɪɹaɪ/
  • Hyphenation: cir‧ri

Noun

cirrus (plural cirri)

1. (biology)
   2. (botany) Synonym of tendril (“a thin, spirally coiling stem that attaches a plant to its support”).
      • 1706, Edward Phillips, compiler, J[ohn] K[ersey the younger], “Cirrus”, in The New World of Words: Or, Universal English Dictionary. […], 6th edition, London: […] J. Phillips, […]; N. Rhodes, […]; and J. Taylor, […], →OCLC, signature [R3], verso, column 1:

        Cirri are taken for thoſe fine Strings, or Hairs, by vvhich ſome Plants faſten themſelves, in order to their Support in creeping along; as Ivy, &c.

   4. (zoology) A thin tendril-like appendage, such as a barbel (“whisker-like sensory organ around the mouth”) of some fish, a cilium of some species of protists, or a foot of some crustaceans of the infraclass Cirripedia.
      • 1828, John Stark, “II.—Mollusca. Class IV. Cirripeda. Order II.—Antennatæ.”, in Elements of Natural History, Adapted to the Present State of the Science, […], volume II (Invertebrata, &c.), Edinburgh: Adam Black and John Stark; London: Longman, Rees, Orme, Brown & Green, →OCLC, page 135:

        Each foot is divided into two parts, one dorsal, the other ventral, and each part has a bundle of subulate bristles and a cirrus.

      • 1833, Charles Bell, “The Substitution of Other Organs for the Hand”, in The Hand: Its Mechanism and Vital Endowments as Evincing Design, London: William Pickering, →OCLC, page 130:

        All creatures which have their skins protected, whether by feathers, or shells, or scales, have an exquisite touch in their mouth, or in the appendages which hang from it. Fishes have cirri which hang from their mouth, and these are equivalent to the feelers or tentacula of insects and crustaceans.

3. (meteorology, often attributive) A principal high-level type of cloud, typically composed of thin, delicate, white filaments or wisps, or narrow bands.

   Synonym: (symbol) Ci

   Hyponym: mare's-tail

   • 1803 July, Luke Howard, “XVIII. On the Modifications of Clouds, and on the Principles of Their Production, Suspension, and Destruction; being the Substance of an Essay Read before the Askesian Society in the Session 1802–3.”, in Alexander Tilloch, editor, The Philosophical Magazine and Journal: Comprehending the Various Branches of Science, the Liberal and Fine Arts, Agriculture, Manufactures, and Commerce, volume XVI, number 62, London: […] [Richard Taylor] for Alexander Tilloch; and sold by Messrs. Richardson, […], →ISSN, →OCLC, pages 99 and 100:

     [page 99] Cirrus. […] Parallel, flexuous, or diverging fibres, extensible in any or in all directions. […] [page 100] In fair weather, with light variable breezes, the sky is seldom quite clear of small groups of the oblique cirrus, which frequently come on from the leeward, and the direction of their increase is to windward.

   • 1921, Jacques W[ardlaw] Redway, “The Moisture of the Air: Fog and Cloud”, in Handbook of Meteorology: A Manual for Cooperative Observers and Students, New York, N.Y.: John Wiley & Sons; London; Chapman & Hall, →OCLC, part I (General Principles), page 75:

     Cirrus clouds moving from the southwest indicate falling temperature; moving from the northwest they indicate the probability of rising temperature. They are the mares' tales and cattails of sailors' cant. Near the horizon, cirrus clouds may have a stratiform appearance.

   • 1952 September 1, Ernest Hemingway, The Old Man and the Sea, New York, N.Y.: Charles Scribner’s Sons, →OCLC, page 61:

     He looked at the sky and saw the white cumulus built like friendly piles of ice cream and high above where the thin feathers of the cirrus against the high September sky.

   • 1996, David Foster Wallace, Infinite Jest […], Boston, Mass.; New York, N.Y.: Little, Brown and Company, →ISBN, page 15:

     The blue sky is glossy and fat with heat, a few thin cirri sheared to blown strands like hair at the rims.

Hyponyms

types of clouds

• cirrocumulus
• cirrostratus
• cirrus aviaticus
• cirrus tractus
• false cirrus
• stratocirrus

Derived terms

• cirral
• cirro-
• cirrus-bag

Related terms

• cirrate
• cirrated
• cirrhopod
• cirrhose
• cirriferous
• cirriform
• cirrigerous
• cirrigrade
• cirriped, cirripede
• cirrocumulus
• cirropodous
• cirrostratus
• cirrous

Translations

synonym of tendril (cognates) — see also tendril

• Catalan: cirrus (ca) m
• Esperanto: ĉiro (eo)
• Galician: cirro m
• Italian: cirro (it) m
• Portuguese: cirro (pt) m
• Spanish: cirro (es) m

thin tendril-like appendage

• Arabic: ذُؤَابَة f (ḏuʔāba)
• Catalan: cirrus (ca) m
• Dutch: cirrus (nl) m
• Finnish: cirrus (fi)
• French: cirre (fr) m
• Galician: cirro m
• German: Cirrus ?
• Italian: cirro (it) m
• Korean: 극모 (ko) (geungmo)
• Portuguese: cirrus ?
• Russian: отро́сток (ru) m (otróstok), у́сик (ru) m (úsik)
• Spanish: cirrus ?, cirro (es) m
• Turkish: sirüs

type of cloud typically composed of thin, delicate, white filaments or wisps, or narrow bands

• Afrikaans: cirruswolk
• Albanian: ciruset
• Arabic: طَخَاء m (ṭaḵāʔ)
• Armenian: փետրավոր ամպեր (pʻetravor amper)
• Asturian: cirru m
• Basque: zirru ?
• Belarusian: перкаватыя воблакі (pjerkavatyja vóblaki), перыстыя воблакі (pjerystyja vóblaki)
• Bulgarian: перест облак m (perest oblak)
• Catalan: cirrus (ca) m
• Chinese:

  Cantonese: 卷雲 / 卷云 (gyun² wan⁴)

  Mandarin: 卷雲 / 卷云 (juǎnyún)

• Corsican: cirru ?
• Czech: řasa (cs) f
• Danish: cirrussky m or f
• Dutch: cirrus (nl) ?, vederwolk f, windveer (nl) f
• Esperanto: ciruso
• Estonian: kiudpilv
• Finnish: cirrus (fi), untuvapilvi (fi)
• French: cirrus (fr) m
• Galician: cirro m
• German: Cirrus ?, Cirruswolke f, Zirrus (de) m, Federwolke (de) f
• Greek: θύσανος (el) m (thýsanos)

  Ancient Greek: θύσανος m (thúsanos)

• Hebrew: צירוס ?
• Hindi: पक्षाभ ? (pakṣābh)
• Hungarian: pehelyfelhő (hu)
• Icelandic: blikufjaðrir f pl, blikutrefjar f pl, klósigar m pl, vatnsklær f pl
• Indonesian: awan sirus
• Irish: ciorras ?
• Italian: cirro (it) m
• Japanese: 巻雲 (ja) (けんうん, ken'un), すじ雲 (sujigumo)
• Kashubian: cirrus
• Kazakh: шарбы бұлттар (şarby būlttar)
• Korean: 권운 (ko) (gwon'un)
• Latin: cirrus m, nubes cirra f
• Latvian: spalvu mākonis m
• Lithuanian: plunksniniai debesys ?
• Lombard: cirro ?
• Macedonian: цирус m (cirus)
• Malay: awan sirus
• Māori: iorangi, pūrehurehu, pūrerehu
• Marathi: तंतुमेघ (tantumegh)
• Mongolian: циррус үүл (cirrus üül)
• Navajo: kʼos áłtʼą́ą́ʼí
• Neapolitan: cirr ?
• Norwegian:

  Bokmål: cirrus m, fjærsky m or f

  Nynorsk: cirrus m

• Occitan: cirrus ?
• Persian: ابر پرسان
• Polish: cirrus (pl) m, chmura pierzasta f
• Portuguese: cirro (pt) m
• Romanian: cirrus m, cirus (ro) m
• Russian: пе́ристое о́блако n (péristoje óblako), пе́ристый (ru) (péristyj) (relational)
• Serbo-Croatian:

  Cyrillic: ци̑рус m

  Latin: cȋrus (sh) m

• Slovak: cirus ?
• Slovene: cirus (sl) ?
• Spanish: cirro (es) m
• Swahili: wingu vundevunde
• Swedish: cirrus (sv) n, cirrusmoln (sv) n, fjädermoln n (informal)
• Tagalog: ruruking alapaap
• Thai: เซอร์รัส
• Turkish: sirüs
• Ukrainian: або пір'ясті ? (abo pirʺjasti), перисті ? (perysti)
• Vietnamese: mây ti
• Waray-Waray: cirrus
• Welsh: cirrus m
• Zulu: amayezi

Further reading

• cirrus (biology) on Wikipedia.Wikipedia
• cirrus cloud on Wikipedia.Wikipedia
• tendril on Wikipedia.Wikipedia
• cirrus (disambiguation) on Wikipedia.Wikipedia

Catalan

Etymology

Learned borrowing from Latin cirrus. Doublet of cerro.

Pronunciation

• IPA^(key): (Central, Balearic, Valencia) [ˈsi.rus]

• Audio (Barcelona):

  (file)

Noun

cirrus m (invariable)

1. (botany) cirrus, tendril

   Synonym: circell

2. (zoology) cirrus (tendril-like appendage)
3. (meteorology) cirrus (cloud)

Further reading

• “cirrus”, in Diccionari de la llengua catalana [Dictionary of the Catalan Language] (in Catalan), second edition, Institute of Catalan Studies [Catalan: Institut d'Estudis Catalans], April 2007
• “cirrus”, in Gran Diccionari de la Llengua Catalana, Grup Enciclopèdia Catalana, 2026
• “cirrus” in Diccionari normatiu valencià, Acadèmia Valenciana de la Llengua.
• Alcover, Antoni Maria; Moll, Francesc de Borja (1963), “cirrus”, in Diccionari català-valencià-balear (in Catalan)

Finnish

Etymology

From New Latin cirrus.

Pronunciation

• IPA^(key): /ˈsirːus/, [ˈs̠irːus̠]
• Rhymes: -irːus
• Syllabification^(key): cir‧rus
• Hyphenation^(key): cir‧rus

Noun

cirrus

1. cirrus (type of cloud)

Declension

Inflection of cirrus (Kotus type 39/vastaus, no gradation)
nominative		cirrus	cirrukset
genitive		cirruksen	cirrusten cirruksien
partitive		cirrusta	cirruksia
illative		cirrukseen	cirruksiin
		singular	plural
nominative		cirrus	cirrukset
accusative	nom.	cirrus	cirrukset
	gen.	cirruksen
genitive		cirruksen	cirrusten cirruksien
partitive		cirrusta	cirruksia
inessive		cirruksessa	cirruksissa
elative		cirruksesta	cirruksista
illative		cirrukseen	cirruksiin
adessive		cirruksella	cirruksilla
ablative		cirrukselta	cirruksilta
allative		cirrukselle	cirruksille
essive		cirruksena	cirruksina
translative		cirrukseksi	cirruksiksi
abessive		cirruksetta	cirruksitta
instructive		—	cirruksin
comitative		See the possessive forms below.

Possessive forms of cirrus (Kotus type 39/vastaus, no gradation)

first-person singular possessor singular plural nominative cirrukseni cirrukseni accusative nom. cirrukseni cirrukseni gen. cirrukseni genitive cirrukseni cirrusteni cirruksieni partitive cirrustani cirruksiani inessive cirruksessani cirruksissani elative cirruksestani cirruksistani illative cirrukseeni cirruksiini adessive cirruksellani cirruksillani ablative cirrukseltani cirruksiltani allative cirrukselleni cirruksilleni essive cirruksenani cirruksinani translative cirruksekseni cirruksikseni abessive cirruksettani cirruksittani instructive — — comitative — cirruksineni second-person singular possessor singular plural nominative cirruksesi cirruksesi accusative nom. cirruksesi cirruksesi gen. cirruksesi genitive cirruksesi cirrustesi cirruksiesi partitive cirrustasi cirruksiasi inessive cirruksessasi cirruksissasi elative cirruksestasi cirruksistasi illative cirrukseesi cirruksiisi adessive cirruksellasi cirruksillasi ablative cirrukseltasi cirruksiltasi allative cirruksellesi cirruksillesi essive cirruksenasi cirruksinasi translative cirrukseksesi cirruksiksesi abessive cirruksettasi cirruksittasi instructive — — comitative — cirruksinesi first-person plural possessor singular plural nominative cirruksemme cirruksemme accusative nom. cirruksemme cirruksemme gen. cirruksemme genitive cirruksemme cirrustemme cirruksiemme partitive cirrustamme cirruksiamme inessive cirruksessamme cirruksissamme elative cirruksestamme cirruksistamme illative cirrukseemme cirruksiimme adessive cirruksellamme cirruksillamme ablative cirrukseltamme cirruksiltamme allative cirruksellemme cirruksillemme essive cirruksenamme cirruksinamme translative cirrukseksemme cirruksiksemme abessive cirruksettamme cirruksittamme instructive — — comitative — cirruksinemme second-person plural possessor singular plural nominative cirruksenne cirruksenne accusative nom. cirruksenne cirruksenne gen. cirruksenne genitive cirruksenne cirrustenne cirruksienne partitive cirrustanne cirruksianne inessive cirruksessanne cirruksissanne elative cirruksestanne cirruksistanne illative cirrukseenne cirruksiinne adessive cirruksellanne cirruksillanne ablative cirrukseltanne cirruksiltanne allative cirruksellenne cirruksillenne essive cirruksenanne cirruksinanne translative cirrukseksenne cirruksiksenne abessive cirruksettanne cirruksittanne instructive — — comitative — cirruksinenne third-person possessor singular plural nominative cirruksensa cirruksensa accusative nom. cirruksensa cirruksensa gen. cirruksensa genitive cirruksensa cirrustensa cirruksiensa partitive cirrustaan cirrustansa cirruksiaan cirruksiansa inessive cirruksessaan cirruksessansa cirruksissaan cirruksissansa elative cirruksestaan cirruksestansa cirruksistaan cirruksistansa illative cirrukseensa cirruksiinsa adessive cirruksellaan cirruksellansa cirruksillaan cirruksillansa ablative cirrukseltaan cirrukseltansa cirruksiltaan cirruksiltansa allative cirrukselleen cirruksellensa cirruksilleen cirruksillensa essive cirruksenaan cirruksenansa cirruksinaan cirruksinansa translative cirruksekseen cirrukseksensa cirruksikseen cirruksiksensa abessive cirruksettaan cirruksettansa cirruksittaan cirruksittansa instructive — — comitative — cirruksineen cirruksinensa

Synonyms

• cirruspilvi
• untuvapilvi

Derived terms

compounds

• cirruspilvi

Further reading

• “cirrus”, in Kielitoimiston sanakirja [Dictionary of Contemporary Finnish]‎^[1] (in Finnish) (online dictionary, continuously updated), Kotimaisten kielten keskuksen verkkojulkaisuja 35, Helsinki: Kotimaisten kielten tutkimuskeskus (Institute for the Languages of Finland), 2004–, retrieved 2 July 2023

Latin

Etymology

The origin is unknown. There are no definitive cognates in other Indo-European languages. Compare Proto-Germanic *hērą (“hair”).

Pronunciation

• (Classical Latin) IPA^(key): [ˈkɪr.rʊs]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈt͡ʃir.rus]

Noun

cirrus m (genitive cirrī); second declension

1. a curl
2. the fringe of clothes
3. the tentacle of an octopus
4. the mane, especially the forelock, of a horse

Declension

Second-declension noun.

	singular	plural
nominative	cirrus	cirrī
genitive	cirrī	cirrōrum
dative	cirrō	cirrīs
accusative	cirrum	cirrōs
ablative	cirrō	cirrīs
vocative	cirre	cirrī

Descendants

• Catalan: cerro
• Galician: cerro
• Italian: cirro
• Portuguese: cerro
• Spanish: cerro

References

• “cirrus”, in Charlton T. Lewis and Charles Short (1879), A Latin Dictionary, Oxford: Clarendon Press
• “cirrus”, in Charlton T. Lewis (1891), An Elementary Latin Dictionary, New York: Harper & Brothers
• "cirrus", in Charles du Fresne du Cange, Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
• “cirrus”, in Harry Thurston Peck, editor (1898), Harper’s Dictionary of Classical Antiquities, New York: Harper & Brothers
• “cirrus”, in William Smith et al., editor (1890), A Dictionary of Greek and Roman Antiquities, London: William Wayte. G. E. Marindin

Polish

Etymology

Learned borrowing from Latin cirrus.

Pronunciation

• IPA^(key): /ˈt͡sir.rus/

• Audio:

  (file)

• Rhymes: -irrus
• Syllabification: cir‧rus

Noun

cirrus m animal

1. (meteorology) cirrus (type of cloud)

   Synonym: chmura pierzasta

Declension

Declension of cirrus

	singular	plural
nominative	cirrus	cirrusy
genitive	cirrusa	cirrusów
dative	cirrusowi	cirrusom
accusative	cirrusa	cirrusy
instrumental	cirrusem	cirrusami
locative	cirrusie	cirrusach
vocative	cirrusie	cirrusy

Further reading

• cirrus in Wielki słownik języka polskiego, Instytut Języka Polskiego PAN
• cirrus in Polish dictionaries at PWN