pillow vs piper

pillow

noun
  • A block under the inner end of a bowsprit. 

  • A soft cushion used to support the head in bed. 

  • A pillow lava. 

  • The socket of a pivot. 

  • A kind of plain, coarse fustian. 

  • A piece of metal or wood, forming a support to equalize pressure; a brass; a pillow block. 

verb
  • To rest as on a pillow. 

piper

noun
  • A bagpiper. 

  • A musician who plays a pipe. 

  • A baby pigeon. 

  • A common European gurnard (Trigla lyra), having a large head, with prominent nasal projection, and with large, sharp, opercular spines. 

  • A sea urchin (Cidaris cidaris) with very long spines, native to the American and European coasts. 

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