A roof composed of two parallel gables forming the shape of the letter M on the end wall.See also: Roof
Illustrated Dictionary of Architecture Copyright © 2012, 2002, 1998 by The McGraw-Hill Companies, Inc. All rights reserved
A roof formed by joining two parallel gable roofs, creating a valley between them, resembling the capital letter M in section.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.