One of a pair of casements, with rabbeted meeting stiles, which is hung in a single frame without a mullion and hinged together so that it can open and fold in a confined space. See also: Chicago window
Illustrated Dictionary of Architecture Copyright © 2012, 2002, 1998 by The McGraw-Hill Companies, Inc. All rights reserved
1. One of a pair of casements, 1, with rabbeted meeting stiles which is hung in a single frame having no mullion.
2. One of two or more casements, 1, which are hinged together so that they can open and fold in a confined space.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.