mermaid vs seiner

mermaid

noun
  • A mythological creature with a woman's head and upper body, and a tail of a fish. 

  • Coloured a brilliant turquoise. 

seiner

noun
  • A fishing vessel used for seining. 

  • A fisherman who uses a seine to catch fish. 

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