gumboot vs overshoe

gumboot

noun
  • A chiton (kind of marine mollusc). 

  • Generic black tea. 

  • A type of boot made of rubber. 

  • A style of popular music traditionally associated with gold miners. 

overshoe

noun
  • To prevent damage to a floor. 

  • To protect from water or mud. 

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