blackfish vs dolphin

blackfish

noun
  • Any of various dark-coloured fish of the Old World, especially the rudderfish (Centrolophus niger). 

  • The Atlantic salmon, Salmo salar, especially a female after spawning. 

  • A pilot whale, genus Globicephalus (occasionally also used for various other whales). 

  • Any of various dark-coloured fishes of Australasia, especially the luderick, Girella tricuspidata, and a freshwater fish, Gadopsis marmoratus. 

  • Either of two dark-coloured fish of the west Atlantic, the tautog of New England (Tautoga onitis) and the black sea bass (Centropristis striata). 

verb
  • To go fishing for blackfish. 

  • To adopt signifiers of black identity (for example, by darkening the skin, or wearing traditionally black hairstyles). 

dolphin

noun
  • A fish, the mahi-mahi or dorado, Coryphaena hippurus, with a dorsal fin that runs the length of the body, also known for iridescent coloration. 

  • A permanent fender designed to protect a heavy boat or coastal structure from the impact of large floating objects such as ice or floating logs. 

  • The dauphin, eldest son of the kings of France. 

  • A man-made semi submerged maritime structure, usually installed to provide a fixed structure for temporary mooring, to prevent ships from drifting to shallow water or to serve as base for navigational aids. 

  • Tursiops truncatus, (Atlantic bottlenose dolphin) the most well-known species. 

  • A carnivorous aquatic mammal in one of several families of order Cetacea, famed for its intelligence and occasional willingness to approach humans. 

  • A spar or buoy held by an anchor and furnished with a ring to which ships may fasten their cables. 

  • A mooring post on a wharf or beach. 

  • A kind of wreath or strap of plaited cordage. 

  • A mass of iron or lead hung from the yardarm, in readiness to be dropped through the deck and the hull of an enemy's vessel to sink it. 

  • A depiction of a fish, with a broad indented fin, usually embowed. 

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