a. Formidable; dread. “Some redoubted knight.” Spenser. [ 1913 Webster ]
Lord regent, and redoubted Burgandy. Shak. [ 1913 Webster ]
a. Not doubted; not called in question; indubitable; indisputable; as, undoubted proof; undoubted hero. -- Un*doubt"ed*ly, adv. [1913 Webster]