rugby vs soccer football

rugby

noun
  • A form of football in which players can hold or kick an ovoid ball; rugby football. The ball cannot be handled forwards and points are scored by touching the ball to the ground in the area past the opponent's territory or by kicking the ball between goalposts and over a crossbar. 

  • The form of the game known as rugby union (see the usage note). 

  • Rubber cement, contact cement. 

verb
  • To play rugby. 

soccer football

noun
  • Synonym of soccer ball 

  • Synonym of association football 

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