fortification

noun4

1. •
   That which fortifies; especially, a work or works erected to defend a place against attack; a fortified place; a fortress; a fort; a castle.

   • “[…] We are engaged in a great work, a treatise on our river fortifications, perhaps? But since when did army officers afford the luxury of amanuenses in this simple republic?[…]” — 1910
2. •
   The act of fortifying; the art or science of fortifying places to strengthen defence against an enemy.
3. •
   An increase in effectiveness, as by adding ingredients.
4. •
   A jagged pattern sometimes seen during an attack of migraine.