See redoubtable in Webster's New World Roget's A-Z Thesaurus II
adjective
Causing or able to cause fear:
appalling, dire, direful, dreadful, fearful, fearsome, formidable, frightful, ghastly, scary, terrible, tremendous. See fearWidely known and esteemed:
celebrated, distinguished, eminent, famed, famous, great, illustrious, notable, noted, preeminent, prestigious, prominent, renowned. See knowledge, respect
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