etymon vs reflex

etymon

noun
  • The original or earlier form of an inherited or borrowed word, affix, or morpheme either from an earlier period in a language's development, from an ancestral language, or from a foreign language. 

  • Meaning as derived and conveyed thereby: The literal meaning of a term according to its origin, which may differ from its usual meaning when the latter relies on idiomatic conventions that are not conveyed by the term alone (that is, they must be known in other ways, such as experience, training, education, or dictionary lookup). 

reflex

noun
  • The descendant of an earlier language element, such as a word or phoneme, in a daughter language. 

  • The ancestor word corresponding to a descendant. 

  • The descendant of anything from an earlier time, such as a cultural myth. 

  • An automatic response to a simple stimulus which does not require mental processing. 

  • Reflection or an image produced by reflection. The light reflected from an illuminated surface to one in shade. 

verb
  • To bend back or turn back over itself. 

  • To respond to a stimulus. 

adj
  • Having greater than 180 degrees but less than 360 degrees. 

  • Illuminated by light reflected from another part of the same picture. 

  • Produced automatically by a stimulus. 

  • Bent, turned back or reflected. 

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