Fortress

[fawr-tris] /ˈfɔr trɪs/

noun
1.
a large fortified place; a fort or group of forts, often including a town; citadel.
2.
any place of exceptional security; stronghold.
/ˈfɔːtrɪs/
noun
1.
a large fort or fortified town
2.
a place or source of refuge or support
verb
3.
(transitive) to protect with or as if with a fortress
n.

early 14c., from Old French forteresse “strong place” (12c.), variant of fortelesse, from Medieval Latin fortalitia, from Latin fortis “strong” (see fort) + English -ess, a fairly uncommon suffix (duress, largess being other examples), from Latin -itia, forming nouns of quality or condition.