WordWeb Online

1. A numbered compartment in a post office where mail is put to be called for
   - Post-Office box, PO Box, POB, call box
    
2. Public box for deposit of mail
   - postbox [Brit], mailbox
    
3. A private box for delivery of mail
   - mailbox

Derived forms: letter boxes

Type of: box, compartment, maildrop

Encyclopedia: Letter box