mailbox mailbag • mailclad · · · Info · Definitions · Synonyms · Characters · · mailbox · · Text Latin · · Script 7 · · Length Definitions · · · (noun) a private box for delivery of mail. Synonyms: letter box. · · Noun Definition 1 (noun) public box for deposit of mail. Synonyms: postbox, letter box. · · Noun Definition 2 Synonyms · · · letter box · · Synonym 1 postbox · · Synonym 2 Characters · · a latin small letter a U+0061 b latin small letter b U+0062 i latin small letter i U+0069 l latin small letter l U+006C m latin small letter m U+006D o latin small letter o U+006F x latin small letter x U+0078