unerringEnglishOxford American Thesaurusunerring adjective with unerring accuracy he hit the gold: unfailing, infallible, unswerving, perfect, flawless, faultless, error-free, impeccable, unimpeachable, sure, true, inevitable, assured, certain, uncanny, deadly, scrupulous, meticulous; informal sure-fire, spot on, dead. ▷antonyms fallible, imperfect.