资料来源 : pyDict

由两个字母组成的

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Biliteral \Bi*lit"er*al\, a. [L. bis twice + littera letter.]
   Consisting of two letters; as, a biliteral root of a Sanskrit
   verb. --Sir W. Jones. -- n. A word, syllable, or root,
   consisting of two letters.