beetling vs coleopteran

beetling

noun
  • The process by which fabrics, etc. are beetled, or beaten with a mallet. 

adj
  • Jutting or protruding, especially of a person's brows. 

coleopteran

noun
  • Any insect of the order Coleoptera; includes the beetles, weevils and fireflies 

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