fink vs mackerel

fink

noun
  • Any of several birds in the family Ploceidae native to southern Africa. 

  • An informer. 

  • A strikebreaker. 

  • A contemptible person. 

verb
  • To betray a trust; to inform on. 

mackerel

noun
  • A true mackerel, any fish of tribe Scombrini (Scomber spp., Rastrelliger spp.) 

  • Certain smaller edible fish, principally true mackerel and Spanish mackerel in family Scombridae, often speckled, 

  • typically Scomber scombrus in the British isles. 

  • Certain other similar small fish in families Carangidae, Gempylidae, and Hexagrammidae. 

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