for·ti·fy / ˈfôrtəˌfī/ • v. (-fies, -fied) [tr.] strengthen (a place) with defensive works so as to protect it against attack: the whole town was heavily fortified| [as adj.] (fortified) a fortified manor house. ∎  strengthen or invigorate (someone) mentally or physically: I was fortified by the knowledge that I was in a sympathetic house. ∎  [often as adj.] (fortified) strengthen (a drink) with alcohol: fortified wine. ∎  increase the nutritive value of (food), esp. with vitamins.DERIVATIVES: for·ti·fi·a·ble adj.for·ti·fi·er n.

fortify XV. — (O)F. fortifier — late L. fortificāre, f. fortis strong; see -FY.
So fortification XV.