overbalance vs overfall

overbalance

verb
  • To lose one's balance; to fall over. 

  • To throw (someone or something) off balance; to cause to capsize. 

  • To be more important than; to outweigh. 

  • To cause an imbalance in (something) by means of excess weight or numbers. 

noun
  • Excess of weight or value; something more than an equivalent. 

overfall

verb
  • To fall over; to topple. 

  • To fall on or spill over so as to cover (something). 

  • To change or affect so as to pervade (something); to come over 

  • To fall over; to spill from an edge or height. 

noun
  • Part of a garment that hangs so as to cover a lower part. 

  • A turbulent section of a body of water, caused by strong currents passing over submerged ridges. 

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