SIGMA


Meaning of SIGMA in English

I. ˈsigmə noun

( -s )

Etymology: Greek, of Semitic origin; akin to Hebrew sāmekh samekh

1. : the 18th letter of the Greek alphabet — symbol Σ or σ or ς; see alphabet tables; compare lunar sigma

2. : the thousandth part of a second : millisecond

3.

a. : standard deviation — symbol σ

b. : the sum of — symbol Σ

4. : a C-shaped sponge spicule

II. noun

or sigma particle

: an unstable subatomic particle of the baryon family existing in positive, negative, and neutral charge states with masses respectively 2328, 2343, and 2333 times the mass of an electron

Webster's New International English Dictionary.      Новый международный словарь английского языка Webster.