untrained         
adjective uk/ʌnˈtreɪnd/ us/ʌnˈtreɪnd/
 未经训练的;未受培训的
never having been taught the skills for a particular job
  untrained staff 未经培训的员工 
 Compare: uneducateduntutored 
Opposite: trained
 to the untrained eye 在外行看来
to someone without the skill or knowledge to judge what they see
  To the untrained eye, most fake diamonds look real. 在外行眼里,大多数假钻石看上去和真的一样。