counterbalance vs equipoise

counterbalance

noun
  • A weight that is put in opposition to an equal weight so it keeps that in balance. 

  • A force or influence that balances, checks or limits an opposite one. 

verb
  • To apply weight in order to balance an opposing weight. 

  • To match or equal in effect when applying opposing force 

equipoise

noun
  • A counterbalance. 

  • A state of balance; equilibrium. 

verb
  • To act or make to act as an equipoise. 

  • To cause to be or stay in equipoise. 

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