Dictionary.net

• A railway passenger car made so as to facilitate seeing the scenery en route; a car open, or with glass sides, or with a kind of open balcony at the rear.

2010 - New Age Dictionary Database
By Oddity Software

• A railway passenger car made so as to facilitate seeing the scenery en route; a car open, or with glass sides, or with a kind of open balcony at the rear.

1913 - Webster's Revised Unabridged Dictionary
By Noah Webster.