HELLACIOUS Meaning of HELLACIOUS in English [ hɛ'leɪʃəs ]■ adjective N. Amer. informal very great, bad, or overwhelming.Derivatives~ly adverb Origin1930s: from hell + -acious , perh. suggested by bodacious . Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004