Simple past tense and past participle of redoubt.(verb)
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Use "redoubted" in a sentence
"Gaita, for example, the wife of Robert Guiscard, a redoubted hero, and the parent of a most heroic race of sons, was herself an Amazon, fought in the foremost ranks of the Normans, and is repeatedly commemorated by our Imperial historian, Anna Comnena."
"The name of the said Knight is the redoubted Robert of Paris."
"Foster, placing his foot on his antagonist, seized on the redoubted sword, so precious in the eyes of its aged owner, and brandished it over his head as a trophy of his conquest."