eraser vs napkin

eraser

noun
  • A thing used to erase or remove something written or drawn by a pen or a pencil. 

  • A thing used to erase something written by chalk on a chalkboard, by marker on a whiteboard, or by some other erasable implement; a chalkboard eraser, whiteboard eraser, etc. 

  • One who erases. 

  • An overwriter program used to prevent data recovery. 

napkin

noun
  • A serviette; a (usually rectangular) piece of cloth or paper used at the table for wiping the mouth and hands for cleanliness while eating. 

  • A nappy (UK), a diaper (American). 

  • A small scarf worn on the head by Christian women (chiefly Roman Catholic and Eastern Orthodox) when entering a church, as a token of modesty. 

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