go to war vs tug

go to war

verb
  • (of a person) To depart, typically from one's home, to join an army at war. 

  • To enter into an armed conflict. 

tug

verb
  • To masturbate. 

  • To tow by tugboat. 

  • To pull or drag with great effort. 

  • To pull hard repeatedly. 

noun
  • A dog toy consisting of a rope, often with a knot in it. 

  • A trace, or drawing strap, of a harness. 

  • A tugboat. 

  • An iron hook of a hoisting tub, to which a tackle is affixed. 

  • A sudden powerful pull. 

  • An act of male masturbation. 

How often have the words go to war and tug occurred in a corpus of books? (source: Google Ngram Viewer )