Firth vs Sea

Firth

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

  • A village in Nebraska. 

  • A city and town in Idaho. 

  • A surname. 

Sea

name
  • A hamlet in Ilminster parish, South Somerset district, Somerset, England (OS grid ref ST3413). 

  • A surname. 

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