0 a wall around the top of a castle, with regular spaces in it through which the people inside the castle can shoot:
The building in front of them was a jumble of towers, crenelations and massive walls.
Soldiers were poised at the crenelations.
He put on his coat, which had been lying across one of the crenelations, and covered his head with a small soft hat.
I leaned upon the crenelations and looked off across the hills, enjoying the loveliness of the sky, in which the planets throbbed superbly.
Within the crumbling crenelations of the ancient battlements twenty-four once large parishes are more or less abandoned or laid waste with their convents, monasteries, and palaces.