We don't have synonyms for reduit yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are reduct, reddit and deduit.
(n) :
Alternative spelling of réduit. [(military, historical, fortifications) a fortified structure such as a citadel or a keep into which the defending troops can retreat when the outer defences are breached.]
(n) :
Alternative spelling of réduit. [(military, historical, fortifications) a fortified structure such as a citadel or a keep into which the defending troops can retreat when the outer defences are breached.]