fortification

中文： 防御工事、工事、堡垒

1. The act of fortifying; the art or science of fortifying places to strengthen defence against an enemy. (countable, uncountable)
2. That which fortifies; especially, a work or works erected to defend a place against attack; a fortified place; a fortress; a fort; a castle. (countable, uncountable)
3. An increase in effectiveness, as by adding ingredients. (countable, uncountable)
4. A jagged pattern sometimes seen during an attack of migraine. (countable, uncountable)

复数 fortifications