1. Lessen the density or solidity of
   "The bones are rarefied" 
2. Make more subtle or refined
   - sublimate, subtilize, subtilise [Brit] 
3. Weaken the consistency of (a chemical substance)
   - attenuate

Derived forms: rarefying, rarefied, rarefies

See also: rarefaction

Type of: alter, change, modify, weaken

• toom
• toon
• Toona
• Toona calantas
• toonie
• tooshie
• toot
• tooter
• tooth
• tooth and nail
• tooth decay
• tooth doctor
• tooth enamel
• tooth fairy
• tooth fungus
• tooth root
• tooth shell
• tooth socket
• toothache
• toothache tree
• toothbrush
• toothbrush tree
• toothed
• toothed spurge
• toothed sword fern