sigma

A noun referring to the 18th letter of the Greek alphabet.

• 🇨🇳希腊字母表的第18个字母，写作Σ（大写）或σ（小写）；在统计学中也指标准差，在数学中常表示求和。

1. Greek letter B1 formal

   The 18th letter of the Greek alphabet, often used in mathematics and science.

   • The symbol sigma is used to denote summation in mathematics.
   • In statistics, sigma represents the standard deviation.
   • The Greek letter sigma looks like a capital E in its uppercase form.

   🇨🇳西格玛

• sigmas plural form
• sigmas' possessive plural form
• sigma's possessive singular form