rarified
adjective
Definitions
Distant from the lives and everyday concerns of ordinary people; esoteric, exclusive, select.
Example: Philosophical debates can be quite rarefied.
Elevated in style or nature, sublime; of high intellectual or moral value.
(of a gas etc.) Less dense than usual; thin.
Example: The air at high altitudes at the top of mountains is rarefied.
verb
Definitions
To make rare, thin, porous, or less dense
To expand or enlarge without adding any new portion of matter to.