noun · 8 senses · updated from the 2026-07-25 local source snapshot
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Pronunciation
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General-American, Received-Pronunciation:/ˈsɪɹəs/
Southern-England:Recorded audio is listed in the source snapshot.
General-American:Recorded audio is listed in the source snapshot.
homophone: cirrous
rhymes with -ɪɹəs
General-American, Received-Pronunciation:/ˈsɪɹaɪ/
CMU ARPABET:S IH1 R AH0 S
Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.
1
noun
Meaning 1
Synonym of tendril (“a thin, spirally coiling stem that attaches a plant to its support”).
Definition source: English Wiktionary via Wiktextract
Topics: biology, botany, natural-sciences
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: tendril
Antonyms: none provided
2
noun
Meaning 2
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.
Definition source: English Wiktionary via Wiktextract
Topics: biology, natural-sciences, zoology
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
3
noun
Meaning 3
A tuft of ornamental feathers.
Definition source: English Wiktionary via Wiktextract
Usage: obsolete
Topics: biology, natural-sciences, ornithology
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
4
noun
Meaning 4
A long, thin, wirelike tail feather.
Definition source: English Wiktionary via Wiktextract
Usage: obsolete
Topics: biology, natural-sciences, ornithology
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
5
noun
Meaning 5
A principal high-level type of cloud, typically composed of thin, delicate, white filaments or wisps, or narrow bands.
Definition source: English Wiktionary via Wiktextract
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: Ci
Antonyms: none provided
6
noun
Meaning 6
a slender flexible animal appendage as on barnacles or crinoids or many insects; often tactile
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
Broader terms: process, outgrowth, appendage
7
noun
Meaning 7
a wispy white cloud (usually of fine ice crystals) at a high altitude (4 to 8 miles)
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: cirrus cloud
Antonyms: none provided
Broader terms: cloud
Narrower terms: mare's tail
8
noun
Meaning 8
usually coiled
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: cirrhus
Antonyms: none provided
Broader terms: tendril
History
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.
Across languages
Translations
110 source translations are retained for this English entry.
Catalan:
cirrus
— synonym of tendril (cognates) — see also tendril
Esperanto:
ĉiro
— synonym of tendril (cognates) — see also tendril
Galician:
cirro
— synonym of tendril (cognates) — see also tendril
Italian:
cirro
— synonym of tendril (cognates) — see also tendril
Portuguese:
cirro
— synonym of tendril (cognates) — see also tendril
Spanish:
cirro
— synonym of tendril (cognates) — see also tendril