esoteric       
adjective uk/ˌiː.səˈter.ɪk/ us/ˌes.əˈter.ɪk/
 极不寻常的;只有少数人(尤指内行)才懂的;限于小圈子的
very unusual and understood or liked by only a small number of people, especially those with special knowledge
  He has an esoteric collection of old toys and games. 他收藏了一批极罕见的老玩具和游戏。 
disapproving or humorous She has a somewhat esoteric taste in clothes. 她的着装品位极不寻常。 
 Compare: exoteric