indirect vs invariable

indirect

verb
  • To access by means of indirection; to dereference. 

adj
  • Not of obvious or immediate cause, but as a secondary result 

  • Not focused straight at the target or subject, but by more subtle means 

  • Not involving the quickest, shortest, or most convenient path 

noun
  • An indirect cost. 

  • An indirect radiator 

invariable

noun
  • Something that does not vary; a constant. 

adj
  • Constant. 

  • Not variable; unalterable; uniform; always having the same value. 

  • That cannot undergo inflection, conjugation or declension. 

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