rarefied
adjective (also rarified) uk/ˈreə.rɪ.faɪd/ us/ˈrer.ə.faɪd/
(LITTLE OXYGEN)
（空气）缺氧的，稀薄的
(of air) with little oxygen
(NOT ORDINARY)
高深精妙的；曲高和寡的
without any of the problems of ordinary life
the rarefied atmosphere of academia 学术界的清高气氛
She moves in rarefied circles. 她在精英小圈子中活动