plimsoll vs trainer

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. 

trainer

noun
  • A running shoe or sneaker. 

  • A person responsible for treating injuries sustained by players during matches; a physiotherapist. 

  • A person who trains another; a coach. 

  • A patch for a video game that applies cheats. 

  • A piece of indoor equipment allowing a bicycle to be ridden while stationary. 

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