fatigue vs inertia

fatigue

noun
  • A weariness caused by exertion; exhaustion. 

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

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

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. 

inertia

noun
  • Lack of activity; sluggishness; said especially of the uterus, when, in labour, its contractions have nearly or wholly ceased. 

  • In a person, unwillingness to take action. 

  • The property of a body that resists any change to its uniform motion; equivalent to its mass. 

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