abecedarian; alphabetic; alphabetical; literal

1. 希臘字母的第六個字母
   The sixth letter of the Greek alphabet.
2. 代數(shù)學(xué)計算的普遍原理，其中通常為字母表中字母的符號，其代表數(shù)字或一組特定數(shù)字中的幾個數(shù)字，它們通過對組中全部數(shù)字都適合的運算法則相聯(lián)系
   A generalization of arithmetic in which symbols, usually letters of the alphabet, represent numbers or members of a specified set of numbers and are related by operations that hold for all numbers in the set.

字母的英語翻譯：