overcoat vs winter coat

overcoat

noun
  • A heavy garment worn over other clothes, for protection from cold or weather. 

verb
  • To apply an exterior coating to. 

winter coat

noun
  • A warm coat, often an overcoat, fit to be worn in winter 

  • An animal's seasonal appearance in winter, notably thicker and/or otherwise camouflaged plumage or fur after (often autumnal) moulting 

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