fortress has definitions from the field of military
1
[ noun ] (military) a fortified defensive structure

Synonyms

fort

Used in print

(Charles Wharton Stork, "Verner von Heidenstam"...)

But he plunges into yet another , this time with Norway , and is killed in an assault on the fortress of Fredrikshall , being only thirty-six years of_age when he died .

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