redoubtable

1 causing fear his next opponent, the reigning champion, would be by far the most redoubtable adversary the young boxer had ever faced Synonyms alarming, dire, direful, dread, dreadful, fearsome, forbidding, formidable, frightening, frightful, ghastly, hair-raising, horrendous, horrible, horrifying, intimidating, fearful, scary, shocking, spine-chilling, terrible, terrifyingRelated Words daunting, demoralizing, disconcerting, discouraging, dismaying, disquieting, distressing, disturbing, perturbing, startling, threatening, troubling, trying, unnerving; bone-chilling, creepy, eerie (also eery), weird; appalling, atrocious, awful, grisly, gruesome (also grewsome), hideous, horrid, macabre, monstrous, nightmarishNear Antonyms calming, comforting, consoling, inviting, lulling, pacifying, quieting, reassuring, relaxing, soothing, tranquilizing (also tranquillizing); nonintimidating, nonthreatening

2 standing above others in rank, importance, or achievement a surprising discovery by one of the most redoubtable figures in Egyptian archaeology Synonyms astral, bright, distinguished, illustrious, luminous, noble, notable, noteworthy, outstanding, preeminent, prestigious, eminent, signal, star, superiorRelated Words celebrated, exalted, famed, famous, glorious, honored, renowned, reputable; infamous, notorious; dominant, paramount, predominantNear Antonyms insignificant, minor, unimportant; average, inferior, mediocre; obscure, uncelebrated, unsung