Rarefy is defined as to become less thin or less dense, or to make or become more refined.
An example of rarefy is add fresh air to a previously suffy room; to rarefy the air.
An example of rarefy is to develop a sense of taste; to rarefy sense of taste.
To make thin or less dense, as air.
To purify or refine.
To become thin or less dense.
To make or become thin, or less dense.
The rarefied mountain air.
To make or become more refined, subtle, or lofty.
A rarefied sense of humor.