duffer vs ibex

duffer

noun
  • A cow that does not produce milk. 

  • An incompetent, indolent, or clumsy person. 

  • Any of various nymphalid butterflies of the genus Discophora. 

  • A player having little skill, especially a golfer who duffs. 

  • A racing pigeon that does not perform well. 

ibex

noun
  • A type of wild mountain goat of the genus Capra, such as the species Capra ibex. 

  • An imaginary creature with serrated horns, somewhat similar to the heraldic antelope. 

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