sigma

See also: Sigma

English

Ancient Greek alphabet

← rho		→ tau
Σ σ ς Ancient Greek: σίγμα
Wikipedia article on sigma

Etymology

From Ancient Greek σῖγμα (sîgma), probably from the root σῑγ- (sīg-) as seen in σίζω (sízō, “to hiss”) + -μα (-ma, nominal suffix).

Pronunciation

• IPA^(key): /ˈsɪɡmə/

• Audio (US):

  (file)

• Rhymes: -ɪɡmə

Noun

sigma (plural sigmas or sigmata)

1. The eighteenth letter of the Classical and Modern Greek alphabets (Σ,  σ), the twentieth letter of Old and Ancient.
   • "Herodotus: On The Customs of the Persians", I.139:

     Their names, which are expressive of some bodily or mental excellence, all end with the same letter---the letter which is called San by the Dorians, and Sigma by the Ionians.

2. (mathematics) The symbol Σ, used to indicate summation of a set or series.
3. (statistics) The symbol σ, used to indicate one standard deviation from the mean, particularly in a normal distribution.
   • 2011, Paul Rincon, (bbc.co.uk) LHC: Higgs boson 'may have been glimpsed'

     None of the spikes seen by the experiments is at much more than the "two sigma" level of certainty.
     A level of "five sigma" is required to claim a discovery, meaning there is less than a one in a million chance the data spike is down to a statistical fluke.

4. (Internet slang) A sigma male (a self-reliant and assertive male).

Derived terms

• delta-sigma converter
• final sigma
• lunate sigma
• sigma additivity
• sigma-algebra
• sigma bond
• sigma darner (Austroaeschna sigma)
• sigma-delta converter
• sigmalike
• sigma male
• sigmate
• sigmatic
• sigmatism
• sigmavirus
• sigmoid
• Six Sigma
• the sigma
• within one sigma

Translations

letter of the Greek alphabet

• Arabic: سِيغْمَا (ar) f (sīḡmā)

  Hijazi Arabic: سِقْما (sigma)

• Asturian: sigma (ast)
• Catalan: sigma (ca) f
• Chinese:

  Mandarin: 西格瑪 / 西格玛 (zh), 西格馬 / 西格马 (zh) (xīgémǎ)

• Czech: sigma n
• Dutch: sigma (nl) m
• Esperanto: sigmo (eo)
• Finnish: sigma (fi)
• French: sigma (fr) m
• Galician: sigma (gl) m
• German: Sigma (de) n
• Greek: σίγμα (el) n (sígma)

  Ancient Greek: σῖγμα n (sîgma)

• Hebrew: סִיגְמָא f (sígma)
• Hungarian: szigma (hu)
• Interlingua: sigma
• Irish: sigme f
• Japanese: シグマ (ja) (shiguma)
• Korean: 시그마 (ko) (sigeuma)
• Malay: sigma
• Māori: hikama
• Persian: سیگما (fa) (sigmâ)
• Polish: sigma (pl) f
• Portuguese: sigma (pt) m
• Russian: си́гма (ru) f (sígma)
• Slovak: sigma n
• Spanish: sigma (es) f
• Swedish: sigma (sv)
• Thai: ซิกมา (sík-mâa)

See also

• (Greek-script letter names) alpha, beta, gamma, delta, epsilon, zeta, eta, theta, iota, kappa, lambda, mu, nu, xi, omicron, pi, rho, sigma, tau, upsilon, phi, chi, psi, omega

Adjective

sigma (comparative more sigma, superlative most sigma)

1. (Internet slang) Possessing characteristics of a sigma male.

Anagrams

• Magis., agism, migas

Catalan

Etymology

Learned borrowing from Latin sigma.

Pronunciation

• IPA^(key): (Central, Balearic) [ˈsiɡ.mə]
• IPA^(key): (Valencia) [ˈsiɡ.ma]

Noun

sigma f (plural sigmes)

1. Sigma; the Greek letter Σ (lowercase σ or ς)
2. (anatomy) sigmoid colon

Derived terms

• sigmàtic
• sigmatisme

Related terms

• sigmoide

Further reading

• “sigma” in Diccionari normatiu valencià, Acadèmia Valenciana de la Llengua.

Czech

Noun

sigma n or f

1. sigma

Declension

when feminine:

Declension of sigma (hard feminine reducible)

	singular	plural
nominative	sigma	sigmy
genitive	sigmy	sigem
dative	sigmě	sigmám
accusative	sigmu	sigmy
vocative	sigmo	sigmy
locative	sigmě	sigmách
instrumental	sigmou	sigmami

Indeclinable when neuter.

Dutch

Etymology

From Ancient Greek σῖγμα (sîgma).

Pronunciation

• IPA^(key): /ˈsɪx.maː/

• Audio:

  (file)

• Hyphenation: sig‧ma

Noun

sigma f (plural sigma's, diminutive sigmaatje n)

1. sigma (letter of the Greek alphabet)

Derived terms

• sigmatisch

Further reading

• sigma on the Dutch Wikipedia.Wikipedia ^nl

Finnish

Etymology

< Ancient Greek σίγμα (sígma)

Greek letter

Σσ	Previous:	rhoo
	Next:	tau

Pronunciation

• IPA^(key): /ˈsiɡmɑ/, [ˈs̠iɡmɑ̝]
• Rhymes: -iɡmɑ
• Syllabification^(key): sig‧ma
• Hyphenation^(key): sig‧ma

Noun

sigma

1. sigma (Greek letter)
2. (Internet slang, neologism, often humorous) short for sigma-uros

Declension

Inflection of sigma (Kotus type 9/kala, no gradation)
nominative		sigma	sigmat
genitive		sigman	sigmojen
partitive		sigmaa	sigmoja
illative		sigmaan	sigmoihin
		singular	plural
nominative		sigma	sigmat
accusative	nom.	sigma	sigmat
	gen.	sigman
genitive		sigman	sigmojen sigmain rare
partitive		sigmaa	sigmoja
inessive		sigmassa	sigmoissa
elative		sigmasta	sigmoista
illative		sigmaan	sigmoihin
adessive		sigmalla	sigmoilla
ablative		sigmalta	sigmoilta
allative		sigmalle	sigmoille
essive		sigmana	sigmoina
translative		sigmaksi	sigmoiksi
abessive		sigmatta	sigmoitta
instructive		—	sigmoin
comitative		See the possessive forms below.

Possessive forms of sigma (Kotus type 9/kala, no gradation)

first-person singular possessor singular plural nominative sigmani sigmani accusative nom. sigmani sigmani gen. sigmani genitive sigmani sigmojeni sigmaini rare partitive sigmaani sigmojani inessive sigmassani sigmoissani elative sigmastani sigmoistani illative sigmaani sigmoihini adessive sigmallani sigmoillani ablative sigmaltani sigmoiltani allative sigmalleni sigmoilleni essive sigmanani sigmoinani translative sigmakseni sigmoikseni abessive sigmattani sigmoittani instructive — — comitative — sigmoineni second-person singular possessor singular plural nominative sigmasi sigmasi accusative nom. sigmasi sigmasi gen. sigmasi genitive sigmasi sigmojesi sigmaisi rare partitive sigmaasi sigmojasi inessive sigmassasi sigmoissasi elative sigmastasi sigmoistasi illative sigmaasi sigmoihisi adessive sigmallasi sigmoillasi ablative sigmaltasi sigmoiltasi allative sigmallesi sigmoillesi essive sigmanasi sigmoinasi translative sigmaksesi sigmoiksesi abessive sigmattasi sigmoittasi instructive — — comitative — sigmoinesi first-person plural possessor singular plural nominative sigmamme sigmamme accusative nom. sigmamme sigmamme gen. sigmamme genitive sigmamme sigmojemme sigmaimme rare partitive sigmaamme sigmojamme inessive sigmassamme sigmoissamme elative sigmastamme sigmoistamme illative sigmaamme sigmoihimme adessive sigmallamme sigmoillamme ablative sigmaltamme sigmoiltamme allative sigmallemme sigmoillemme essive sigmanamme sigmoinamme translative sigmaksemme sigmoiksemme abessive sigmattamme sigmoittamme instructive — — comitative — sigmoinemme second-person plural possessor singular plural nominative sigmanne sigmanne accusative nom. sigmanne sigmanne gen. sigmanne genitive sigmanne sigmojenne sigmainne rare partitive sigmaanne sigmojanne inessive sigmassanne sigmoissanne elative sigmastanne sigmoistanne illative sigmaanne sigmoihinne adessive sigmallanne sigmoillanne ablative sigmaltanne sigmoiltanne allative sigmallenne sigmoillenne essive sigmananne sigmoinanne translative sigmaksenne sigmoiksenne abessive sigmattanne sigmoittanne instructive — — comitative — sigmoinenne third-person possessor singular plural nominative sigmansa sigmansa accusative nom. sigmansa sigmansa gen. sigmansa genitive sigmansa sigmojensa sigmainsa rare partitive sigmaansa sigmojaan sigmojansa inessive sigmassaan sigmassansa sigmoissaan sigmoissansa elative sigmastaan sigmastansa sigmoistaan sigmoistansa illative sigmaansa sigmoihinsa adessive sigmallaan sigmallansa sigmoillaan sigmoillansa ablative sigmaltaan sigmaltansa sigmoiltaan sigmoiltansa allative sigmalleen sigmallensa sigmoilleen sigmoillensa essive sigmanaan sigmanansa sigmoinaan sigmoinansa translative sigmakseen sigmaksensa sigmoikseen sigmoiksensa abessive sigmattaan sigmattansa sigmoittaan sigmoittansa instructive — — comitative — sigmoineen sigmoinensa

Derived terms

compounds

• sigmasidos
• sigmasuoli
• sigma-uros

Further reading

• “sigma”, 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 3 July 2023

French

Pronunciation

• IPA^(key): /siɡ.ma/

• Audio (France (Lyon)):

  (file)

Noun

sigma m (invariable)

1. sigma (Greek letter)

Further reading

• “sigma”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012

Icelandic

Noun

sigma n (genitive singular sigma, nominative plural sigmu) or rarely
sigma f (genitive singular sigmu, nominative plural sigmur)

1. sigma (Greek letter)

Declension

Declension of sigma (neuter)

	singular		plural
	indefinite	definite	indefinite	definite
nominative	sigma	sigmað	sigmu	sigmun
accusative	sigma	sigmað	sigmu	sigmun
dative	sigma	sigmanu	sigmum	sigmunum
genitive	sigma	sigmans	sigma	sigmanna

or rarely

Declension of sigma (feminine)

	singular		plural
	indefinite	definite	indefinite	definite
nominative	sigma	sigman	sigmur	sigmurnar
accusative	sigmu	sigmuna	sigmur	sigmurnar
dative	sigmu	sigmunni	sigmum	sigmunum
genitive	sigmu	sigmunnar	sigma	sigmanna

Italian

Etymology

From Ancient Greek σῖγμα (sîgma), σίγμα (sígma).

Pronunciation

• IPA^(key): /ˈsiɡ.ma/
• Rhymes: -iɡma
• Hyphenation: sìg‧ma

Noun

sigma m or f (invariable)

1. sigma, specifically:
   1. the name of the Greek-script letter Σ/σ, ς
   2. (mathematics) the symbol Σ, used to indicate summation of a set or series
   3. (statistics) the symbol σ, used to indicate one standard deviation from the mean, specifically in a normal distribution

Derived terms

• sigmatismo/sigmacismo

Noun

sigma m (invariable)

1. (anatomy) sigmoid colon

Anagrams

• sgami

Polish

Etymology

Learned borrowing from Ancient Greek σῖγμα (sîgma), from Phoenician 𐤔 (š‬ /⁠šīn⁠/).

Pronunciation

• IPA^(key): /ˈsiɡ.ma/

• Audio:

  (file)

• Rhymes: -iɡma
• Syllabification: sig‧ma

Noun

sigma f

1. sigma (Greek letter Σ, σ/ς)
2. (mathematics) sigma (symbol Σ, used to indicate summation of a set or series)

Declension

Declension of sigma

	singular	plural
nominative	sigma	sigmy
genitive	sigmy	sigm
dative	sigmie	sigmom
accusative	sigmę	sigmy
instrumental	sigmą	sigmami
locative	sigmie	sigmach
vocative	sigmo	sigmy

Further reading

• sigma in Polish dictionaries at PWN

Portuguese

Pronunciation

 

• (Brazil) IPA^(key): /ˈsi.ɡi.mɐ/, /ˈsiɡ.mɐ/

• (Brazil) IPA^(key): /ˈsi.ɡi.mɐ/, /ˈsiɡ.mɐ/
  • (Southern Brazil) IPA^(key): /ˈsiɡ.ma/, /ˈsi.ɡi.ma/

• (Portugal) IPA^(key): /ˈsi.ɡmɐ/ [ˈsi.ɣmɐ]

Noun

sigma m (plural sigmas)

1. sigma (name of the Greek letter Σ, σ)

Further reading

• “sigma”, in Dicionário Aulete Digital (in Portuguese), Rio de Janeiro: Lexikon Editora Digital, 2008–2026
• “sigma”, in Dicionário Priberam da Língua Portuguesa (in Portuguese), Lisbon: Priberam, 2008–2026

Romanian

Etymology

Borrowed from Ancient Greek σῖγμα (sîgma) or French sigma.

Noun

sigma m (plural sigma)

1. sigma (Greek letter)

Declension

	singular			plural
	indefinite	definite		indefinite	definite
nominative-accusative	sigma	sigmaul		sigma	sigmai
genitive-dative	sigma	sigmaului		sigma	sigmalor
vocative	sigmaule			sigmalor

Spanish

Pronunciation

• IPA^(key): /ˈsiɡma/ [ˈsiɣ̞.ma]

• Audio (Costa Rica):

  (file)

• Rhymes: -iɡma
• Syllabification: sig‧ma

Noun

sigma f (plural sigmas)

1. sigma; the Greek letter Σ, σ

Further reading

• “sigma”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025