tug vs twitch

tug

verb
  • To pull hard repeatedly. 

  • To masturbate. 

  • To tow by tugboat. 

  • To pull or drag with great effort. 

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. 

twitch

verb
  • To jerk sharply and briefly. 

  • To spot or seek out a bird, especially a rare one. 

  • To cause to twitch; spasm. 

  • To perform a twitch; spasm. 

noun
  • A stick with a hole in one end through which passes a loop, which can be drawn tightly over the upper lip or an ear of a horse and twisted to keep the animal quiet during minor surgery. 

  • A brief, small (sometimes involuntary) movement out of place and then back again; a spasm. 

  • Action of spotting or seeking out a bird, especially a rare one. 

  • A brief, contractile response of a skeletal muscle elicited by a single maximal volley of impulses in the neurons supplying it. 

  • The sudden narrowing almost to nothing of a vein of ore. 

  • A trip taken in order to observe a rare bird. 

  • couch grass (Elymus repens; a species of grass, often considered as a weed) 

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