borer vs pocketknife

borer

noun
  • A knife fit for a stabbing. 

  • A person who bores or drills; a person employed to drill bore holes. 

  • A cyclostome, such as a hagfish, which bores into injured, dead, or decaying sea creatures to feed on their flesh. 

  • One of the many types of mollusc that bore into soft rock. 

  • A tool used for drilling. 

  • A tedious person; a person who bores others; a bore. 

  • An insect or insect larva that bores into wood. 

pocketknife

noun
  • A knife with blades or tools that the user can fold or retract into its handle, and of a size small enough for carrying safely and handily in a pocket, especially when suited to heavier duty uses or ad hoc applications outdoors or in workshops. 

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