sigma

[ sig-muh ]
/ ˈsɪg mə /

noun

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
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Examples 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

Medicine 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.

Science 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.