rarefied

adjective
1
understood or experienced by only a very small group of people who share a particular area of knowledge or activity
خاص و ویژه, تخصصی, ویژه خواص, خاص, ویژه
2
containing less oxygen than usual
کم‌اکسیژنی, کم‌اکسیژن, رقیق‌شده, هوای رقیق
Climbers may experience difficulty breathing in the rarefied air at high altitudes.