fishtail vs nod

fishtail

verb
  • To move with the tail swinging from side to side in this way. 

  • To swing the back of a vehicle (originally an aircraft) from side to side. 

  • To cause the back of (a vehicle) to swing from side to side. 

noun
  • The skidding of the back of a vehicle from side to side. 

  • A kind of chisel with a flared blade. 

  • The tail of a fish, or an object resembling this. 

nod

verb
  • To sway, move up and down. 

  • To signify by a nod. 

  • To incline the head up and down, as to indicate agreement. 

  • To allude to something. 

  • To make a mistake by being temporarily inattentive or tired 

  • To briefly incline the head downwards as a cursory greeting. 

  • To fall asleep while under the influence of opiates. 

  • To gradually fall asleep. 

  • To head; to strike the ball with one's head. 

noun
  • A nomination. 

  • An instance of inclining the head up and down, as to indicate agreement, or as a cursory greeting. 

  • Approval. 

  • A reference or allusion to something. 

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