Associations to the word «Sigma»

Wiktionary

SIGMA, noun. The eighteenth letter of the Classical and Modern Greek, the twentieth letter of Old and Ancient.
SIGMA, noun. (mathematics) The symbol Σ, used to indicate summation of a set or series.
SIGMA, noun. (statistics) The symbol σ, used to indicate one standard deviation from the mean, particularly in a normal distribution.
SIGMA ADDITIVITY, noun. (analysis) Alternative form of σ-additivity
SIGMA BOND, noun. (chemistry) A covalent atomic bond that is rotationally symmetric about its axis.

Dictionary definition

SIGMA, noun. The 18th letter of the Greek alphabet.

Wise words

The difference between the right word and the almost right word is the difference between lightning and a lightning bug.
Mark Twain