keg vs spare tire

keg

noun
  • A round, traditionally wooden container of lesser capacity than a barrel, often used to store beer. 

verb
  • To store in a keg. 

spare tire

noun
  • Used other than figuratively or idiomatically: see spare, tire. 

  • An extra wheel carried as a replacement in case of a flat. 

  • Excess weight or fat accumulated near the waist. 

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