What does the word ballast mean?

Usage examples for ballast

  1. 5. Salt is an important article in all our return cargoes; because, being carried as ballast, its freight costs nothing. – Memoir, Correspondence, And Miscellanies, From The Papers Of Thomas Jefferson by Thomas Jefferson
  2. And, indeed, it does exhibit Schiller's historical style at its best, there being here, in comparison with his earlier work, somewhat less of heavy philosophical ballast. – The Life and Works of Friedrich Schiller by Calvin Thomas
  3. We are the ballast of the new order. – Another Sheaf by John Galsworthy