overshoe vs welly

overshoe

noun
  • To prevent damage to a floor. 

  • To protect from water or mud. 

welly

noun
  • Force on a pedal or increase to any fuel or power for an engine or motor. 

  • Wellington boot. 

  • Force or effort. 

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