sigma

[ sig-muh ]
/ ˈsɪg mə /

noun

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

QUIZZES

Can You Remember Your Favorite Words Of The Day From March?
Even if you’re a habitué of Word of the Day, you haven’t seen our March words in these ways! Challenge yourself to our comprehensive quiz!
Question 1 of 15
What does "habitué" mean?

Origin of sigma

1600–10; < Latin < Greek sígma
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for sigma

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
[ sĭgmə ]

n.

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.

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.