edder vs ophidian

edder

noun
  • An adder or snake. 

  • Flexible wood worked into the top of hedge stakes, to bind them together. 

ophidian

noun
  • Any species of the suborder Serpentes; a snake or serpent. 

adj
  • Of or pertaining to the suborder Serpentes; of, related to, or characteristic of a snake or serpent. 

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