excrescent vs extrusive

excrescent

adj
  • Growing out in an abnormal or morbid manner or as a superfluity. 

noun
  • A sound in a word without etymological reason. 

  • A growing mutation, usually abnormal. 

extrusive

adj
  • Jutting out; extruding. 

  • Of rocks: forced, while in a plastic or molten state, on to the Earth's surface to lie atop existing rocks. 

noun
  • Rock which has been formed through volcanic extrusion. 

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