'Fortify' in the Bible

Raise up a signal flagagainst the walls of Babylon;fortify the watch post;set the watchmen in place;prepare the ambush.For the Lord has both planned and accomplishedwhat He has threatenedagainst those who live in Babylon.

Though Babylon should mount up to heaven, and though she should fortify the height of her strength, yet from me shall spoilers come unto her, saith the LORD.