What does the word mainstay mean?

Usage examples for mainstay

  1. With the perfect and self- sacrificing courage which he always showed, he did not shrink from this new demand, although Ezekiel was the prop and mainstay of the house. – Daniel Webster by Henry Cabot Lodge
  2. If the facts ever come to light it will probably be found that Burghley was Bacon's mainstay for financial support. – The Mystery of Francis Bacon by William T. Smedley