crenelPronunciation: /ˈkrɛn(ə)l/ (also crenelle /krɪˈnɛl/)Definition of crenel noun an indentation in the battlements of a fort or castle, used for shooting or firing missiles through. Origin: late 15th century: from Old French, based on popular Latin crena 'notch'crenel in other Oxford dictionaries Definition of crenel in the US English dictionary