ΣシグマFreq.FrequencyTop 10,000Meanings1nounsigmaThe 18th letter of the Greek alphabet; used in mathematics, science, and engineering.数すう学がくでΣは総そう和わを表あらわす記き号ごうだ。In mathematics, Σ is the symbol for summation.この式しきのσは標ひょう準じゅん偏へん差さを意い味みしている。The σ in this formula stands for standard deviation.