Cocker vs Slough

Cocker

name
  • A river in Cumbria, England, which joins the Derwent at Cockermouth. 

  • A surname. 

  • A short river in Lancashire, England, which flows into the Lune estuary. 

Slough

name
  • A town in east Berkshire, England (formerly Buckinghamshire), close to Heathrow Airport. 

  • A borough and unitary authority (Slough Borough Council) in Berkshire. 

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