Dictionary.com

sigma

[ sig-muh ]
/ ˈsɪg mə /
Save This Word!

noun
the 18th letter of the Greek alphabet: Σ, σ, ς.
the consonant sound represented by this letter.
QUIZ
CAN YOU ANSWER THESE COMMON GRAMMAR DEBATES?
There are grammar debates that never die; and the ones highlighted in the questions in this quiz are sure to rile everyone up once again. Do you know how to answer the questions that cause some of the greatest grammar debates?
Question 1 of 7
Which sentence is correct?

Origin of sigma

1600–10; <Latin <Greek sígma
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use sigma in a sentence

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

Scientific definitions for sigma

sigma
[ sĭgmə ]

A sigma baryon.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
FEEDBACK