caravan vs mudguard

caravan

noun
  • A furnished vehicle towed behind a car, etc., and used as a dwelling when stationary. 

  • A convoy or procession of travelers, their vehicles and cargo, and any pack animals, especially camels crossing a desert. 

verb
  • To travel in a caravan (procession). 

  • To travel and/or live in a caravan (vehicle). 

mudguard

noun
  • A cover over the wheels of a vehicle, or a flap behind that wheel, to prevent water and mud being projected. 

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