embrasure

Etymology

From Middle French embrasure.

noun

1. (architecture, military) Any of the indentations between the merlons of a battlement; an opening in a wall or parapet through which ordnance can be fired.
2. (figurative) Any small protected space.
3. The slanting indentation in a wall for a door or window, such that the space is larger on the inside than the outside.
   When the fit had spent itself he walked weakly to the window and, lifting the sash, sat in a corner of the embrasure and leaned his elbow upon the sill. 1916, James Joyce, chapter 3, in A Portrait of the Artist as a Young Man
   Now he stands in a window embrasure, Liz's prayer book in hand. 2009, Hilary Mantel, Wolf Hall, Fourth Estate, published 2010, page 155
4. (obsolete) An embrace.