fairing vs mudguard

fairing

noun
  • A structure on various parts of a vehicle, for example an aircraft, automobile, or motorcycle, that produces a smooth exterior and reduces drag. 

  • A type of small gingerbread biscuit; a ginger nut. 

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 fairing and mudguard occurred in a corpus of books? (source: Google Ngram Viewer )