dolphin vs orca

dolphin

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

  • 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. 

  • 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. 

  • 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. 

orca

noun
  • A sea mammal (Orcinus orca) related to dolphins and porpoises, commonly called the killer whale. 

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