Crenelle

Crenelle is a noun borrowed from French crénelle. In architecture and fortifications, a crenelle refers to a small gap or opening in a crenellated parapet, situated between merlons. The plural crenelles is used in French; English uses crenel or crenellated edge to describe the feature. The term describes the notch that allows defenders to observe or fire through the wall while remaining protected by the merlons. In historical contexts, crenellations are characteristic of medieval castles and city walls and vary in form from square to rounded merlons, with crenels of differing widths.

Beyond fortifications, the word crenelle occasionally appears in architectural descriptions of decorative battlements on buildings and fences, especially in translations from French sources. In these uses, crenelation indicates the patterned, tooth-like profile of a parapet.

Note: In English-language architectural terminology, crenel is the more common term, whereas crenelle is primarily the French form and appears in some historical or translated texts. See also crenellation, merlon, parapet.