chalkboard vs weatherboard

chalkboard

noun
  • A slate or enamel board for writing on with chalk; a predecessor to a whiteboard. 

verb
  • To write or draw on a chalkboard. 

weatherboard

noun
  • Any of a series of horizontal boards used to cover the exterior of a timber-framed building; clapboard. 

  • The windward side of a vessel. 

  • A plank placed over an opening to keep out driven water. 

verb
  • To cover with a weatherboard. 

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