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sigma

American  
[sig-muh] / ˈsɪg mə /

noun

  1. the 18th letter of the Greek alphabet: Σ, σ, ς.

  2. the consonant sound represented by this letter.


sigma British  
/ ˈsɪɡmə /

noun

  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

"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

sigma Scientific  
/ sĭgmə /
  1. A sigma baryon.


Etymology

Origin of sigma

First recorded in 1600–10; from Latin, from Greek sígma

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

"Slay", "sigma" and "skibidi" were chosen as the top three slang words, which OUP said demonstrated the role of social media in influencing children's vocabulary.

From BBC Jan. 22, 2025

If you’re lurking in dark corners of the internet, there’s alpha, beta and sigma males.

From Salon Oct. 14, 2023

"Our work shows that the dark photon hypothesis is preferred over the standard model hypothesis at a significance of 6.5 sigma, which constitutes evidence for a particle discovery."

From Science Daily Sep. 18, 2023

At the time, the discrepancy between theory and experiment was, in particle-physics parlance, 4.2 sigma.

From Scientific American Aug. 10, 2023

Record, average time, in sigma, and number of false reactions.

From Vocational Psychology: Its Problems and Methods by Hollingworth, Harry L.

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