Firth vs Mole

Firth

name
  • A city and town in Idaho. 

  • A village in Nebraska. 

  • A surname. 

  • A small village in north-east Mainland, Shetland Islands council area, Scotland (OS grid ref HU4473). 

Mole

name
  • A river in Devon, England, tributary to the Taw. 

  • A river in Surrey, England, tributary to the Thames. 

  • A surname. 

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