The term originated in about the 14th century from the Old French word , "to fortify with batailles" (fixed or movable turrets of defence). The word crenel derives from the ancient French cren (modern French cran), meaning a notch, mortice or other gap cut out often to receive another element or fixing. The modern French word for crenel is creneau, also used to describe a gap of any kind, for example a parking space at the side of the road between two cars, interval between groups of marching troops or a timeslot in a broadcast.