fatigue vs knacker

fatigue

verb
  • To tire or make weary by physical or mental exertion. 

  • To lose so much strength or energy that one becomes tired, weary, feeble or exhausted. 

  • To cause to undergo the process of fatigue. 

  • To wilt a salad by dressing or tossing it. 

  • To undergo the process of fatigue; to fail as a result of fatigue. 

noun
  • Weakening and eventual failure of material, typically by cracking leading to complete separation, caused by repeated application of mechanical stress to the material. 

  • A weariness caused by exertion; exhaustion. 

  • A menial task or tasks, especially in the military. 

knacker

verb
  • To tire out, exhaust. 

  • To reprimand. 

noun
  • One who makes knickknacks, toys, etc. 

  • A member of the Travelling Community; a Gypsy. 

  • One who slaughters and (especially) renders worn-out livestock (especially horses) and sells their flesh, bones and hides. 

  • A person of lower social class; a chav, skanger or scobe. 

  • One who dismantles old ships, houses, etc. and sells their components. 

  • A harness maker. 

  • One of two or more pieces of bone or wood held loosely between the fingers, and struck together by moving the hand; a clapper. 

  • A testicle. 

  • An old, worn-out horse. 

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