Noun
The act of fortifying; the art or science of fortifying places in order to defend them against an enemy.
That which fortifies; especially, a work or works erected to defend a place against attack; a fortified place; a fortress; a fort; a castle.
Source: Webster's dictionaryThe system of fortification by wall and towers may be made safest by the addition of earthen ramparts. Vitruvius
When the master-builder has taken up the work concerned, he is to re-establish securely any place where the fortification has fallen into ruins. Let him reinforce and also rebuild it. Shulgi
After fortification, this number declined to around 3,000. Source: Internet
After the prolonged Siege of Sevastopol (1854–55) the base fell, exposing Russia's inability to defend a major fortification on its own soil. Source: Internet
An abatis, abattis, or abbattis is a field fortification consisting of an obstacle formed (in the modern era) of the branches of trees laid in a row, with the sharpened tops directed outwards, towards the enemy. Source: Internet
Apart from the Riegersburg, the Schloßberg was the only fortification in the region that never fell to the Ottoman Turks. Source: Internet