Letter box Meaning, Definition & Usage

  1. noun a numbered compartment in a post office where mail is put to be called for
    Post-Office box; POB; call box; PO Box.
  2. noun public box for deposit of mail
    postbox; mailbox.
  3. noun a private box for delivery of mail
    mailbox.

WordNet

Definitions
  1. a box for the reception of letters to be mailed or delivered.

Webster 1913