sigma

[ sig-muh ]

/ ˈsɪg mə /

noun

the 18th letter of the Greek alphabet: Σ, σ, ς.

the consonant sound represented by this letter.

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Origin of sigma

1600–10; < Latin < Greek sígma

Words nearby sigma

sigint, sigismund, sigismund ii, sigla, siglos, sigma, sigma baryon, sigma factor, sigma particle, sigmate, sigmatism

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for sigma

Lohse rushes Sigma Alpha Epsilon, gets a bid, endures pledge term, and then submits to the dehumanizing rigors of Hell Night.
An Ivy League Frat Boy’s Shallow Repentance|Stefan Beck|November 24, 2014|DAILY BEAST
Pledging, also known as initiation, will now be abolished by Sigma Alpha Epsilon nationally across its 240 chapters.
Deadly Frat Rituals Are Banned Thanks to Technology|Joe Concha|March 10, 2014|DAILY BEAST
And all of these records were summed up, integrated, into the "Sigma" curve.
The Vortex Blaster|Edward Elmer Smith
It is to be observed that the Grecians in foreign words continually omitted the Nu final, and substituted a Sigma.
A New System; or, an Analysis of Antient Mythology. Volume I.|Jacob Bryant

Sigma is thanked: but he will see that we could not now alter the size of our volumes.
Notes and Queries, Number 169, January 22, 1853|Various
Take colour, for instance; and we shall perceive that in the Dromius sigma, Rossi, it is sensibly affected.
On the Variation of Species, with Especial Reference to the Insecta ; Followed by an Inquiry into the Nature of Genera|Thomas Vernon Wollaston
Sigmoid, curved in two directions, like the letter S, or the Greek sigma.
The Elements of Botany|Asa Gray

British Dictionary definitions for sigma

sigma

/ (ˈsɪɡmə) /

noun

the 18th letter in the Greek alphabet (Σ, σ, or, when final, ς), a consonant, transliterated as S

maths the symbol Σ, indicating summation of the numbers or quantities indicated

Word Origin for sigma

Greek, of Semitic origin; related to Hebrew samekh

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

Medical definitions for sigma

sigma

[ sĭg′mə ]

n.

The 18th letter of the Greek alphabet.

Scientific definitions for sigma

sigma

[ sĭg′mə ]

A sigma baryon.