rarefied

adjective3

1. •
   Less dense than usual; thin.

   • The air at high altitudes at the top of mountains is rarefied.
2. •
   Distant from the lives and everyday concerns of ordinary people; esoteric, exclusive, select.

   • Philosophical debates can be quite rarefied.
3. •
   Elevated in style or nature, sublime; of high intellectual or moral value.