A window sash which opens inward and is hinged at the bottom; when open, air passes over the top of the sash. See also: French window
Illustrated Dictionary of Architecture Copyright © 2012, 2002, 1998 by The McGraw-Hill Companies, Inc. All rights reserved
hospital window, hopper window
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.