tug vs wood screw

tug

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

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

  • A tugboat. 

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

  • A sudden powerful pull. 

  • An act of male masturbation. 

verb
  • To masturbate. 

  • To tow by tugboat. 

  • To pull or drag with great effort. 

  • To pull hard repeatedly. 

wood screw

noun
  • A screw designed for a wood or a similar material, with a point, a relatively coarse thread, a thick shank, and, usually, an unthreaded portion of the shank at the head end. 

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