- the 18th letter of the Greek alphabet: Σ, σ, ς.
- the consonant sound represented by this letter.
Origin of sigma
1600–10; < Latin < Greek sígma
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples 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
November 24, 2014
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
March 10, 2014
And all of these records were summed up, integrated, into the "Sigma" curve.The Vortex Blaster
Edward Elmer Smith
Sigma is thanked: but he will see that we could not now alter the size of our volumes.
Sigmoid, curved in two directions, like the letter S, or the Greek sigma.The Elements of Botany
Take colour, for instance; and we shall perceive that in the Dromius sigma, Rossi, it is sensibly affected.
There he began to find himself, and became one of the popular men in his class and in the Sigma Phi Fraternity.Frank H. Nelson of Cincinnati
Warren C. Herrick
- 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
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
Word Origin and History for sigma
18th letter of the Greek alphabet, corresponding to Latin S, a metathesis of Hebrew samekh. In uncial writing, shaped like an S or a C.
Online Etymology Dictionary, © 2010 Douglas Harper
- The 18th letter of the Greek alphabet.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- A sigma baryon.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.