fantail vs swallowtail

fantail

noun
  • A brimmed hat with just the back of the brim turned up. 

  • Any of several birds, of the genus Rhipidura, from Asia, Australia and New Zealand. 

  • Any of several goldfish having a large fan-shaped tail. 

  • Any of several domestic varieties of pigeon having a fan-shaped tail. 

  • An overhanging deck at the stern of a ship. 

  • A small windmill mounted at right angles to the sails, at the rear of the windmill, used to turn the cap automatically to bring it into the wind. 

swallowtail

noun
  • A type of tailcoat with two long tapering tails.ᵂᵖ 

  • The forked tail of a swallow. 

  • Anything, such as a burgee, of a similar forked shape. 

  • Any of various butterflies of the family Papilionidae, many of which have a long extension to each hindwing. 

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