pocketknife vs whittle

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. 

whittle

noun
  • A knife; especially, a pocket knife, sheath knife, or clasp knife. 

verb
  • To cut or shape wood with a knife. 

  • To reduce or gradually eliminate something (such as a debt). 

  • To make eager or excited; to excite with liquor; to inebriate. 

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