VIGESIMAL Meaning of VIGESIMAL in English [ vɪ'dʒɛsɪm(ə)l , vʌɪ- ]■ adjective rare relating to or based on the number twenty.OriginC17: from L. vigesimus (from viginti 'twenty') + -al . Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004