vagariousEnglishOxford New American Dictionaryvagarious /vəˈɡerēəs, , vəˈɡɛriəs , vāˈɡerēəs, veɪˈɡɛriəs / ▸ adjective rare erratic and unpredictable in behavior or direction. – ORIGIN late 18th century (in the sense ‘changing, inconstant’): from vagary + -ous.