plimsoll vs sneaker

plimsoll

noun
  • A rubber-soled lace-up canvas shoe for sports or onboard ships; a precursor of trainers. 

  • The plimsoll symbol ⦵ (or o) that is used as a superscript in the notation of thermodynamics to indicate an arbitrarily chosen non-zero reference point. 

sneaker

noun
  • An athletic shoe with a soft, rubber sole. A trainer. 

  • A sneaker male. 

  • One who sneaks. 

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