We admit it – crenellation is a weird word. The best way to remember this word is to think of castles. You know that gap-toothed / saw blade type design that makes up the parapet of the stereotypical castle? That’s crenellation. Technically, the crenellation parts are the gaps and the merlons are the “teeth,” but you can refer to the whole thing as crenellation. Not only were they decorative, but they were also functional as they were used for defense purposes. We guess that’s why crenellation is also called battlement. Go figure.