Definition from Wiktionary, the free dictionary
machicolation (plural machicolations)
- An opening between the corbels which support a projecting parapet, or in the floor of a gallery or the roof of a portal, shooting or dropping missiles upon assailants attacking the base of the walls. Also, the construction of such defenses, in general, when of this character.
- The act of discharging missiles or pouring burning or melted substances upon assailants through such apertures.