WordWeb Online

1. Having low density
   "rarified gasses"
   - rare, rarefied
    
2. Of high moral or intellectual value; elevated in nature or style
   - exalted, elevated, sublime, grand, high-flown, high-minded, lofty, rarefied, idealistic, noble-minded

1. Make more complex, intricate, or rich
   "rarify a design or pattern"
   - complicate, refine, elaborate

See also: noble, thin

Type of: alter, change, modify