Definitions
1.Nounsigma, specifically:
the name of the Greek-script letter Σ/σ, ς
the symbol Σ, used to indicate summation of a set or series
the symbol σ, used to indicate one standard deviation from the mean, specifically in a normal distribution
2.Nounthe name of the Greek-script letter Σ/σ, ς
3.Nounthe symbol Σ, used to indicate summation of a set or series
4.Nounthe symbol σ, used to indicate one standard deviation from the mean, specifically in a normal distribution
5.Nounsigmoid colon