Crossword puzzle clue "fortress for short"

to fortify

the nest of a bird of prey, also EYRIE, EYRY

(Spanish) a kind of poplar tree

(Arabic) a Spanish fortress or palace

a tower or an elevated work, used for the defense, or in the siege, of a fortified place, also BASTILLE

a tower at the corner of a fortification

a heavily armoured warship of the largest type having many large-calibre guns