SEXAGENARIAN Meaning of SEXAGENARIAN in English [ ˌsɛksədʒɪ'nɛ:rɪən ]■ noun a person who is between 60 and 69 years old.OriginC18: from L. sexagenarius (based on sexaginta 'sixty') + -an . Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004