yūsen
1. mail boat
Noun
#71864
1. mail boat
1. Mail ship; Steamer
1. By mail steamer; While sending by mail steamer
1. Mail boat; Steamer
1. If/when by mail steamer; If/when by ship mail
1. Was a mail steamer.; Was a passenger ship.
1. It is not a mail boat.; It is not a steamer.
1. If it were a mail steamer; When it's a mail steamer
1. Probably a ship.; Likely a liner.
1. It's not a passenger ship.; It isn't a passenger ship.