Search the dictionary A Chinese word or character, or English Draw a character Search 4 entries. xīgémǎ 西格马 sigma (Greek letter Σ, σ) xīgémǎ 西格馬 sigma (Greek letter Σ, σ) xīgémǎ 西格玛 sigma (Greek letter Σ, σ) xīgémǎ 西格瑪 sigma (Greek letter Σ, σ)