Wimperg

A wimperg is a German and Dutch word for a Gothic ornamental gable with tracery over windows or portals, which were often accompanied with pinnacles. It was a typical element in Gothic Architecture especially in cathedral architecture. Wimpergs often had crockets or other decorative elements in the Gothic style. The intention behind the wimperg was the perception of increased height.

In the Middle Ages the wimperg was applied rarely. The more common, rectangular (and generally very narrow) windows were merlons—these used as defense against projectiles.

Source: http://www.architektur-lexikon.de/lexikon/wimperg.htm