the 18th letter of the greek alphabet: Σ, σ, ς.
the consonant sound represented by this letter.

1600–10; < Latin < Greek sígma Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To sigma
World English Dictionary
sigma (ˈsɪɡmə)
1.  the 18th letter in the Greek alphabet (Σ, σ, or, when final, ς), a consonant, transliterated as S
2.  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 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
American Heritage
Medical Dictionary

sigma sig·ma (sĭg'mə)

Symbol ς 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.
Cite This Source
American Heritage
Science Dictionary
sigma   (sĭg'mə)  Pronunciation Key 
A sigma baryon.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Computing Dictionary

SIGMA definition

A scientific visual programming environment from NASA.
The Free On-line Dictionary of Computing, © Denis Howe 2010
Cite This Source
Example sentences
By definition, three sigma events are not supposed to come in battalions.
If we're on the topic of alternatives how about some form of six-sigma normalization of the prices of goods and wages.
Sigma receptors are effected by cocaine, as cocaine functions as a sigma ligand agonist.
Copyright © 2014, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature