ethereal vs metaphysical

ethereal

adj
  • Consisting of ether; hence, exceedingly light or airy; tenuous; spiritlike; characterized by extreme delicacy, as form, manner, thought, etc. 

  • Pertaining to the (real or hypothetical) upper, purer air, or to the higher regions beyond the earth or beyond the atmosphere. 

  • To do with diethyl ether. 

  • Pertaining to the immaterial realm, as symbolically represented by, or (in earlier epochs) conflated with, such atmospheric and extra-atmospheric concepts. 

metaphysical

adj
  • Immaterial, supersensual, not physical (more properly, "beyond" that which is physical). 

  • Being an adherent of the philosophy of metaphysics. 

  • Of or pertaining to metaphysics. 

How often have the words ethereal and metaphysical occurred in a corpus of books? (source: Google Ngram Viewer )