Citadel (4)
'citadel' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for fortress that I've seen before include "Protective structure" , "Castle" , "Strong point" , "Perhaps keep" , "it's hard to break into" .)
'citadel' is the definition.
(a citadel is a fortified city)
This is all the clue.
(Other definitions for fort that I've seen before include "Strategic position" , "& 22 US Army post" , "& 4 Down Army post in USA" , "Defensive stronghold" , "Citadel" .)
'citadel' is the definition.
(synonyms)
This is all the clue.
(Other definitions for bastion that I've seen before include "A projecting fortification to increase angle of fire" , "Obtains in fortified place or stronghold" , "staunch supporter" , "Stronghold, fortification" , "Fortified place near hostile territory" .)