concrete vs ethereal

concrete

noun
  • An extract of herbal materials that has a semi-solid consistency, especially when such materials are partly aromatic. 

  • Specifically, a building material created by mixing cement, water, and aggregate such as gravel and sand. 

  • Sugar boiled down from cane juice to a solid mass. 

  • A dessert of frozen custard with various toppings. 

  • A term designating both a quality and the subject in which it exists; a concrete term. 

verb
  • To solidify: to change from being abstract to being concrete (actual, real). 

  • To cover with or encase in concrete (building material). 

adj
  • Made of concrete, a building material. 

  • Being or applying to actual things, not abstract qualities or categories. 

  • Real, actual, tangible. 

  • Particular, specific, rather than general. 

  • United by coalescence of separate particles, or liquid, into one mass or solid. 

ethereal

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

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

  • 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. 

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