a written, typed, or printed communication, especially one sent in an envelope by mail or messenger.
he sent a letter to Mrs. Falconer
同义词：
written messagemessagewritten communicationcommunicationnotelinemissiveepistledispatchreportbulletincorrespondencenewsinformationintelligencewordmailpost
3
the precise terms of a statement or requirement; the strict verbal interpretation.
we must be seen to keep the spirit of the law as well as the letter
