mailcoach

US and Canadian mailcar

noun

a railway coach specially constructed for the transportation of mail

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Examples from the Web for mailcoach

Historical Examples of mailcoach

When the system of mailcoach lines reached its highest perfection, the mails were handled as they are today.
Historic Highways of America (Vol. 10)
Archer Butler Hulbert