solidity vs substantive

solidity

noun
  • Moral firmness; validity; truth; certainty. 

  • The state or quality of being solid. 

  • The solid contents of a body; volume; amount of enclosed space. 

substantive

verb
  • to make a word belonging to another part of speech into a substantive (that is, a noun) or use it as a noun 

noun
  • Part of a text that carries the meaning, such as words and their ordering. 

adj
  • Constituting the substance of content rather than its style, and thus always nontrivial. 

  • Of or pertaining to a substantive. 

  • actually and legally held, as distinct from an acting, temporary or honorary rank or appointment 

  • Having substance; enduring; solid; firm; substantial. 

  • of the essence or essential element of a thing. 

  • applying to essential legal principles and rules of right. 

  • Depending on itself; independent. 

  • of a dye that does not need the use of a mordant to be made fast to that which is being dyed 

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