sixpence vs tanner

sixpence

noun
  • A former British coin worth sixpence, first minted in 1551. 

tanner

noun
  • A former British coin worth six old pence. 

  • A type of commercially-fished crab, Chionoecetes bairdi or Chionoecetes opilio. 

  • A person whose occupation is to tan hides, or convert them into leather by the use of tan. 

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