PERTINACIOUS Meaning of PERTINACIOUS in English [ ˌpə:tɪ'neɪʃəs ]■ adjective formal stubborn; persistent.Derivatives~ly adverb~ness nounpertinacity noun OriginC17: from L. pertinax , pertinac- 'holding fast' + -ous . Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004