Citadel rebuilt, in a manner of speaking (7)
I believe the answer is:
dialect
'in a manner of speaking' is the definition.
(I've seen this before)
'citadel rebuilt' is the wordplay.
'rebuilt' indicates an anagram.
'citadel' with letters rearranged gives 'DIALECT'.
(Other definitions for dialect that I've seen before include "Regional form of word" , "Regional language form" , "Local form of language" , "Local language variation" , "Manner of speaking" .)