Embrasure (noun)

An indentation or recess in a wall or fortification to allow for the firing of weapons or for light and ventilation.

Origin:

Middle english: from old french, from enbraser, based on braser 'to warm', from latin brasa 'live coals, warmth'. the original sense was 'an opening in a wall to allow warmth from a fire to circulate', later 'a wall opening for firing through' (mid 16th century), then 'an indentation in a wall for a window or door' (late 16th century).

Examples:

1. The castle was equipped with numerous embrasures to provide defense against invading forces.
2. The embrasures in the castle walls were designed to allow the defenders to fire upon the enemy without exposing themselves to return fire.
3. The narrow and deeply recessed embrasures offered excellent protection for the archers stationed inside.
4. The castle's embrasures were some of the largest and most elaborate of their time, and served as a model for later fortifications.
5. The embrasures in the castle walls provided a stunning view of the surrounding countryside, and were a favorite spot for visitors.