1RAREa rarefied place, organization, or type of activity is only available to or understood by a small group of people – used to show disapproval 〔地方、组织、活动〕只限于小圈子内的;曲高和寡的;玄妙的〔含贬义〕
the rarefied atmosphere of academia
曲高和寡的学术界氛围
2.DNHErarefied air is the air in high places, which has less oxygen than usual 〔空气〕稀薄的,含氧量低的