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.

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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

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sigma Scientific  

/ sĭg′mə /

1. A sigma baryon.

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Etymology

Origin of sigma

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